You plan to migrate a web application to Azure. The web application is (AZ-900)

Correct answer: B) Platform as a Service (PaaS).
PaaS solutions, such as Azure App Service, provide a fully managed platform for hosting web applications. With PaaS, the cloud provider (in this case, Microsoft) is responsible for managing the underlying infrastructure, including the operating system, middleware, and runtime environments. This significantly reduces the administrative effort required by the organization to manage the web application.

In contrast:
Software as a Service (SaaS) is not applicable in this scenario, as it refers to a complete, ready-to-use application provided by a cloud vendor, which is not the case for a custom-built web application.
Infrastructure as a Service (IaaS) would require the organization to manage the underlying virtual machines, operating systems, and other infrastructure components, which would increase the administrative effort.
Database as a Service (DaaS) is a specific PaaS offering for databases, which could be a part of the overall PaaS solution, but it does not address the management of the web application itself.
By recommending a PaaS solution, such as Azure App Service, the organization can focus on developing and deploying the web application, while the cloud provider handles the management of the underlying infrastructure, including scaling, patching, and monitoring. This approach minimizes the administrative effort required by the organization, which aligns with the goal of the migration.