What does the term "key fob" refer to in modern vehicles?

The term "key fob" refers to a remote control device used to lock and unlock doors and start the vehicle. This small electronic device typically fits on a keychain and often utilizes radio frequency or Bluetooth technology to communicate with the vehicle. When a driver approaches the car with their key fob, the car recognizes it and allows the doors to be unlocked without needing to manually insert a key. Additionally, many modern vehicles equipped with push-button start systems depend on the key fob to start the engine, providing convenience and enhanced security by reducing the likelihood of unauthorized access.

The other options listed do not accurately describe the function of a key fob; vehicle insurance involves coverage and liability, a measuring device for tire pressure is not related to keyless entry or starting systems, and tracking fuel efficiency pertains to monitoring and optimizing fuel usage, which doesn't involve the key fob's primary functions.