Final answer:
The most common mistake that drivers make when backing is failing to look both ways behind them.
Step-by-step explanation:
The correct answer is a. True.
When backing, it is essential for drivers to look both ways behind them to ensure there are no obstacles or hazards that may interfere with their movement. By checking for any potential dangers, such as pedestrians or other vehicles, drivers can avoid accidents and safely navigate in reverse.
For example, a driver who fails to look behind them before reversing may collide with a car approaching from the rear, causing a rear-end collision. Therefore, it is crucial for drivers to be aware of their surroundings and perform the necessary checks before backing up.