Which of the following is an example of an operating system?

The selected answer, Windows, is correct because it is a well-known operating system that manages computer hardware and software resources and provides services for computer programs. An operating system acts as an intermediary between users and the computer hardware, allowing the execution of programs, managing files, and providing a user interface. Windows, developed by Microsoft, is widely used in personal computers and serves various functions critical to running applications and managing system resources.

In contrast, options such as Amazon Web Services represent a cloud computing platform rather than an operating system; Adobe Photoshop and Microsoft Excel are applications designed for specific tasks—image editing and spreadsheet management, respectively—rather than systems that manage hardware or run software applications. Thus, Windows is the only choice that properly fits the definition and function of an operating system.