Final answer:
The stop light on a truck should be illuminated when you apply the foot brake. This is a mandatory safety feature that signals a truck's intent to stop to other drivers, which is crucial for preventing accidents. option b is correct.
Step-by-step explanation:
The question addresses a legal requirement regarding vehicle operations, specifically about when a truck's stop light must be illuminated. The correct option is b. when you apply the foot brake. Stop lights in vehicles, which are either red or amber in color, are safety features designed to alert other motorists of a vehicle's deceleration or intention to stop. Whenever the driver of a truck applies the foot brake, the stop light should immediately light up to communicate this action to others on the road. This is a key aspect of vehicle safety protocols that enhance communication between drivers and help prevent collisions.
Notably, the presence of an emergency situation, such as a pregnant woman about to give birth in the back seat, does not alter the requirement for stop lights to illuminate when the foot brake is applied. Likewise, neither engaging the windshield wipers, selecting park mode, nor pressing the gas pedal should directly trigger the activation of a stop light. It is the application of the brake pedal that initiates this safety signal.
Learning the proper function and use of vehicle safety features, including the role of static and kinetic friction in bringing a vehicle to a gentle stop, is part of becoming a responsible and safe driver. Appropriate use of vehicle lights and understanding the mechanics behind vehicle stopping distances contribute to overall road safety.