How should the vehicle's accelerator pedal function?

The accelerator pedal in a vehicle is designed to control the amount of fuel and air mixture that enters the engine, thereby regulating the vehicle's speed. Proper functioning of the accelerator pedal is crucial for safe driving, allowing for smooth acceleration and deceleration as dictated by driving conditions.

Option B is correct because the footbrake, or brake pedal, is intended to bring all wheels of the vehicle to a complete stop when applied firmly. This simultaneous braking ensures that the vehicle comes to a halt in a stable manner, contributing to safe stopping without causing loss of control. If the brakes did not stop all tires simultaneously, it could lead to skidding or losing control of the vehicle, especially in emergency situations.

The other options do not pertain to the fundamental function of the accelerator pedal. Only having the handbrake engage in emergencies does not capture the necessary stopping capability of the brake system as a whole. Describing the accelerator as working inconsistently undermines the reliability necessary for vehicle control and performance. Furthermore, limiting the handbrake's effectiveness to only the front tires fails to recognize the design and intent of the braking system, which is to secure the vehicle's stability in all scenarios.