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Box 1: No
A PaaS solution does not provide access to the operating system.  The Azure Web Apps service provides an environment for you to host your web applications.  Behind the scenes, the web apps are hosted on virtual machines running IIS.  However, you have no direct access to the virtual machine, the operating system or IIS. 
Box 2: Yes
A PaaS solution that hosts web apps in Azure does provide the ability to scale the platform automatically. This is known as autoscaling.  Behind the scenes, the web apps are hosted on virtual machines running IIS.  
Autoscaling means adding more load balanced virtual machines to host the web apps. 
Box 3: Yes
PaaS provides a framework that developers can build upon to develop or customize cloud-based applications. 
PaaS development tools can cut the time it takes to code new apps with pre-coded application components built into the platform, such as workflow, directory services, security features, search and so on. 
References:
https://azure.microsoft.com/en-gb/overview/what-is-paas/

Box 1: Yes
Traditionally, IT expenses have been considered a Capital Expenditure (CapEx). Today, with the move to the cloud and the pay-as-you-go model, organizations have the ability to stretch their budgets and are shifting their IT CapEx costs to Operating Expenditures (OpEx) instead. This flexibility, in accounting terms, is now an option due to the “as a Service” model of purchasing software, cloud storage and other IT related resources. 
Box 2: No
Two virtual machines using the same size could have different disk configurations.  Therefore, the monthly costs could be different. 
Box 3: Yes
When an Azure virtual machine is stopped, you don’t pay for the virtual machine.  However, you do still pay for the storage costs associated to the virtual machine.  The most common storage costs are for the disks attached to the virtual machines.  There are also other storage costs associated with a virtual machine such as storage for diagnostic data and virtual machine backups. 
References:
https://meritsolutions.com/capex-vs-opex-cloud-computing-blog/

When you are implementing a Software as a Service (SaaS) solution, you are responsible for configuring the SaaS solution.  Everything else is managed by the cloud provider. 
SaaS requires the least amount of management. The cloud provider is responsible for managing everything, 
and the end user just uses the software. 
Software as a service (SaaS) allows users to connect to and use cloud-based apps over the Internet. 
Common examples are email, calendaring and office tools (such as Microsoft Office 365). 
SaaS provides a complete software solution which you purchase on a pay-as-you-go basis from a cloud service provider. You rent the use of an app for your organization and your users connect to it over the Internet, usually with a web browser. All of the underlying infrastructure, middleware, app software and app data are located in the service provider’s data center. The service provider manages the hardware and software and with the appropriate service agreement, will ensure the availability and the security of the app and your data as well. 
References:
https://azure.microsoft.com/en-in/overview/what-is-saas/
https://docs.microsoft.com/en-gb/learn/modules/principles-cloud-computing/5-types-of-cloud-services

Fault tolerance is the ability of a system to continue to function in the event of a failure of some of its components. 
In this question, you could have servers that are replicated across datacenters. 
Availability zones expand the level of control you have to maintain the availability of the applications and data on your VMs. Availability Zones are unique physical locations within an Azure region. Each zone is made up of one or more datacenters equipped with independent power, cooling, and networking. To ensure resiliency, there are a minimum of three separate zones in all enabled regions. The physical separation of Availability Zones within a region protects applications and data from datacenter failures. 
With Availability Zones, Azure offers industry best 99.99% VM uptime SLA. By architecting your solutions to use replicated VMs in zones, you can protect your applications and data from the loss of a datacenter. If one zone is compromised, then replicated apps and data are instantly available in another zone. 
References:
https://docs.microsoft.com/en-us/azure/virtual-machines/windows/manage-availability

A private cloud is hosted in your datacenter.  Therefore, you cannot close your datacenter if you are using a private cloud. 
A public cloud is hosted externally, for example, in Microsoft Azure.  An organization that hosts its infrastructure in a public cloud can close its data center. 
Public cloud is the most common deployment model. In this case, you have no local hardware to manage or keep up-to-date – everything runs on your cloud provider's hardware.  
Microsoft Azure is an example of a public cloud provider. 
In a private cloud, you create a cloud environment in your own datacenter and provide self-service access to compute resources to users in your organization. This offers a simulation of a public cloud to your users, but you remain completely responsible for the purchase and maintenance of the hardware and software services you provide. 
References:
https://docs.microsoft.com/en-gb/learn/modules/principles-cloud-computing/4-cloud-deployment-models

When planning to migrate a public website to Azure, you must plan to pay monthly usage costs. This is because Azure uses the pay-as-you-go model.

Azure App Service and Azure SQL databases are examples of Azure PaaS solutions. Therefore, this solution does meet the goal.

Azure App Service is a PaaS (Platform as a Service) service.  However, Azure virtual machines are an IaaS (Infrastructure as a Service) service.  Therefore, this solution does not meet the goal.

Azure App Service is a PaaS (Platform as a Service) service.  However, Azure Storage accounts are an IaaS (Infrastructure as a Service) service.  Therefore, this solution does not meet the goal.

Elasticity in this case is the ability to provide additional compute resource when needed and reduce the compute resource when not needed to reduce costs.  Autoscaling is an example of elasticity. 
Elastic computing is the ability to quickly expand or decrease computer processing, memory and storage resources to meet changing demands without worrying about capacity planning and engineering for peak usage. Typically controlled by system monitoring tools, elastic computing matches the amount of resources allocated to the amount of resources actually needed without disrupting operations. With cloud elasticity, a company avoids paying for unused capacity or idle resources and doesn’t have to worry about investing in the purchase or maintenance of additional resources and equipment. 
References:
https://azure.microsoft.com/en-gb/overview/what-is-elastic-computing/