Which Alibaba Cloud service allows for the hosting of web applications?

The correct choice is Alibaba Cloud Elastic Compute Service (ECS), as it is specifically designed to provide scalable and flexible compute capabilities for hosting a variety of applications, including web applications. ECS allows users to create and configure virtual servers, which can be used to deploy web apps directly.

With ECS, developers gain full control over the server environment, including the operating system and the software stack, which is essential for hosting complex web applications that require specific configurations or resources. ECS offers the ability to scale resources up or down based on demand, ensuring that web applications can perform optimally under varying loads.

The other services mentioned do not primarily serve the purpose of hosting web applications. For instance, while the Alibaba Cloud Web Hosting Service is indeed used for hosting, it is not mentioned as an option here, which makes ECS the best choice from the provided list. ApsaraDB for RDS is focused on providing managed relational database services rather than hosting applications. Alibaba Cloud Function Compute is designed for event-driven serverless computing, which suits certain use cases but is not intended for traditional web app hosting like ECS is.