A software team is deploying a web app and does not want to manage the underlying OS or hardware. Which Azure service model fits this use case?

Platform as a Service (PaaS) is the correct choice because it provides a complete development and deployment environment in the cloud, allowing developers to build, run, and manage applications without the complexity of building and maintaining the infrastructure typically associated with developing and launching an app. This includes not having to manage the underlying operating system, virtual machines, or hardware. IaaS (Infrastructure as a Service) would require the team to manage the operating system, even though the hardware is virtualized. SaaS (Software as a Service) is a complete, ready-to-use application, not a platform for developing one. Bare metal hosting involves managing all aspects of the server, including the physical hardware, which is the opposite of the team's requirement.