Final answer:
The Finder is where a user can navigate to all of the iMac's contents.
Step-by-step explanation:
The correct answer is 4) Finder. On an iMac, the Finder is the primary application that allows users to navigate through the computer's contents. It provides a graphical interface for accessing files, folders, and applications. Users can open the Finder by clicking on its icon in the Dock or by pressing Command + Space to open Spotlight and then searching for 'Finder'.