Little cameras in the car made doing what easier?
Options:
- technical difficulties
- heat up
- carpooler
- set off
- back up Let's give stream of consciousness first:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Cameras can be used for back up. Back up is needed in a car. Back up is made easier by cameras.
Therefore, the answer is back up.