Which type of fluids must be checked during a vehicle inspection?

Checking brake fluid, coolant, and oil levels is critical during a vehicle inspection because these fluids play essential roles in the safe and efficient operation of the vehicle.

Brake fluid is vital for the proper functioning of the braking system, ensuring that the brakes respond effectively when engaged. Low brake fluid levels can lead to a decrease in braking power, posing a serious safety risk.

Coolant is necessary for regulating the engine's temperature. If the coolant is low or contaminated, the engine can overheat, leading to severe damage and costly repairs. Ensuring adequate coolant levels helps maintain optimal engine performance and longevity.

Oil levels must also be checked because engine oil lubricates the moving parts of the engine, reducing wear and tear and ensuring smooth operation. Insufficient oil can lead to increased friction, overheating, and potential engine failure.

In contrast, the other options focus on a more limited scope of fluids. Checking only oil levels neglects both brake and coolant fluid, which are equally critical for safety and performance. The reference to only coolant levels fails to address the importance of brake fluid, and while transmission fluid and windshield washer fluid are important, they are not considered essential parts of a standard vehicle inspection in the context of critical operational safety like brake fluid and coolant.