A CIO is comparing IaaS and PaaS. Which characteristic best distinguishes PaaS?

PaaS (Platform as a Service) is distinguished by providing a complete development and deployment environment in the cloud, including operating systems, programming language execution environments, databases, and web servers. The key differentiator is the inclusion of built-in development tools and services, allowing developers to focus on writing code without managing the underlying infrastructure. "Offers only virtual machines" is incorrect because IaaS (Infrastructure as a Service) primarily offers virtual machines, while PaaS abstracts this layer. "Requires full OS and patch management" is characteristic of IaaS, where the user is responsible for these tasks; PaaS handles them. "Provides physical infrastructure" is incorrect as this is the responsibility of the cloud provider for all service models (IaaS, PaaS, SaaS).