Which of the following is an example of a subdomain?

A subdomain is a division of a main domain that can be used to organize different sections of a website or provide specific services under the primary domain. In this case, "www.example" represents a subdomain of the primary domain "example.com."

The "www" prefix often indicates the web server hosting the primary site, while other prefixes can be designated for different purposes, such as "blog.example.com" or "store.example.com." Subdomains are useful in structuring content, separating services, or even handling different geographical areas for a website.

Other options represent different elements of web domains. For instance, "uk.com" is a second-level domain under the top-level domain (TLD) ".com," while "example.com" is the main domain itself. The option "com" is simply the top-level domain, which is not a subdomain but serves as a category for domains that follow it.