What is a primary reason for having a functioning brake system in a vehicle?

A primary reason for having a functioning brake system in a vehicle is to ensure the safety of passengers and other road users. The brake system is essential for controlling the speed and stopping power of the vehicle, which is crucial for preventing accidents. A reliable brake system allows drivers to stop quickly when necessary, reducing the risk of collisions with other vehicles, pedestrians, or obstacles on the road. This safety function is a top priority in vehicle design and regulation, emphasizing the importance of brake system maintenance and inspection to protect both occupants and the general public.

Other options may seem relevant to vehicle operation but do not address the fundamental purpose of the brake system. Enhancing fuel efficiency and engine cooling pertain to the vehicle's performance and maintenance but are not directly related to braking functions. Improving vehicle speed also does not relate to brakes, as the primary role of brakes is to slow down or stop the vehicle, not to make it go faster. Thus, the critical focus on safety highlights why a functioning brake system is vital.