What is the primary purpose of a rearview mirror?

The primary purpose of a rearview mirror is to help you see vehicles behind you while driving. This is crucial for safe driving, as it allows you to monitor the traffic behind your vehicle, making it easier to change lanes, merge, or back up without colliding with another vehicle. Utilizing the rearview mirror effectively helps ensure situational awareness, which is a key factor in preventing accidents and maintaining safe driving practices.

The other options describe functions that are not related to the main role of the rearview mirror. While aesthetics can play a part in the overall design of a vehicle, the rearview mirror's essential function is safety and visibility rather than appearance. Adjusting the interior temperature pertains to climate control features, and indicating fuel levels relates to the fuel gauge in the instrument panel, all of which are separate functionalities from that of the rearview mirror.