Final answer:
The correct way to wear the shoulder belt in a vehicle for safety is across your chest and over your shoulder.
Step-by-step explanation:
The correct way to wear the shoulder belt in a vehicle for safety is option C) across your chest and over your shoulder. This ensures that the shoulder belt is properly positioned to protect you in the event of a crash. Wearing the shoulder belt behind your back, under your arm, or loosely draped over your lap can result in serious injury in a collision. By wearing the shoulder belt across your chest and over your shoulder, you decrease the risk of injury and increase your safety while driving.