Which of the following is/are example of cloud computing?

Cloud Computing refers to the on-demand delivery of computing services—including servers, storage, databases, networking, software, and analytics—over the internet ("the cloud") on a flexible pay-as-you-go pricing model.

The industry systematically breaks cloud architectures down into specific delivery ecosystems, all represented in the question:

Software as a Service (SaaS): A massive tier of cloud computing where entire end-user business programs are fully hosted, maintained, and delivered dynamically through a cloud vendor.

Web Applications: The physical software interfaces built inside internet browsers that rely entirely on back-end cloud infrastructures to process and manipulate user transactions.

Software Plus Services: A highly effective hybrid model that leverages local client machine performance for software tasks while offloading data synchronization, collaborative tools, and security updates to distributed cloud data centers.

Because every entry represents a core example or architectural methodology of cloud computing, Option D is the correct answer.