Screech! When a driver pushes on the brake pedal, it initiates a process that causes the vehicle to stop in motion. We literally trust braking systems with our lives every time we get into a vehicle or
cross at a busy intersection. How does this life-critical process work? It begins when the pedal is
pushed. At this moment brake fluid is reljased into the braking mechanisms. As the fluid collects,
this creates a leverage, which causes a friction to be applied. This friction will create a force that
will cause the wheels to stop and allow you to reach your destination safely. Beep! Beep!

This question is incomplete, here´s the complete question.

Screech! When a driver pushes on the brake pedal, it initiates a process that causes the vehicle to  stop in motion. We literally trust braking systems with our lives every time we get into a vehicle or

cross at a busy intersection. How does this life-critical process work? It begins when the pedal is  pushed. At this moment brake fluid is reljased into the braking mechanisms. As the fluid collects,  this creates a leverage, which causes a friction to be applied. This friction will create a force that  will cause the wheels to stop and allow you to reach your destination safely. Beep! Beep!

What is the main/central idea of the passage?

How a braking system functions on an automobile

Trusting automotive braking systems

Brake fluid being released in the area where the breaking mechanisms are

There is no main/central idea

How a braking system functions on an automobile

Explanation:

This passage´s main idea is not meant to focus on brake fluids or the trustworthiness of braking systems.  

The main idea is how braking systems work as a whole. To do so, the passage describes the process that ensues since pushing on the brake pedal and until the vehicle stops, including the brake fluid being released, creating leverage and friction that make the wheels stop.

d) sarah's natural reaction to being accepted into college suggests that she has no other dreams.