Final answer:
The positioning of your rear-view mirror becomes critical in a situation where you may be struck from the rear.
Step-by-step explanation:
The positioning of your rear-view mirror becomes critical if you are in a situation where you may be struck from the rear. When driving, it is important to have a clear view of the rear to be able to respond quickly to any potential danger. By adjusting your rear-view mirror properly, you can increase your awareness of what is happening behind your vehicle.