Final answer:
It is important to check the traffic behind you when changing lanes, driving down steep hills, or slowing down to ensure safety and prevent accidents, so the answer is d) all of the above.
Step-by-step explanation:
When to Check Traffic Behind You
It is important to check the traffic behind you in several instances for safety reasons. Specifically, you should check behind you when changing lanes to ensure that the way is clear and you won't collide with another vehicle. Checking is also critical when driving down steep hills because you may need to slow down, and you have to be aware of the traffic that may be approaching at a higher speed. Additionally, checking is necessary when you are slowing down, to make sure that the driver behind you is aware and has time to react to avoid a rear-end collision.
Therefore, the correct answer to the question is d) all of the above. Being aware of your surroundings at all times when driving is essential for the safety of everyone on the road. Whether changing lanes, moving down steep gradients, or decelerating, regular checks help in preventing accidents.