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

Linux is a prominent example of a desktop operating system because it provides a user-friendly interface suitable for personal computers and laptops, allowing users to perform various tasks such as word processing, internet browsing, and multimedia consumption. It supports a wide range of applications and is known for its customization capability, making it appealing for both novice and advanced users.

The other options represent different types of operating systems. Android is primarily designed for mobile devices, focusing on touch interfaces and mobile applications, which distinguishes it from traditional desktop environments. Windows Server serves as a network operating system intended for managing servers and network resources rather than typical desktop functionalities. iOS, similar to Android, is optimized for mobile devices, providing an interface designed specifically for smartphones and tablets. Hence, Linux stands out as the correct choice for a desktop operating system in this context.