What can cause a vehicle's air conditioning system to fail?

The air conditioning system in a vehicle can fail due to a variety of issues, with low refrigerant levels, leaks, or a faulty compressor being among the most common causes. Refrigerant is the substance that cools the air in the A/C system, and if it is low due to leaks or has not been properly serviced, the system cannot effectively generate cold air. A faulty compressor, which is crucial for pressurizing the refrigerant and circulating it through the system, can also lead to an A/C failure. When either of these issues occurs, it directly impacts the performance of the A/C system, causing it to fail.

In contrast, the other options, such as faulty spark plugs, worn brake pads, and dirty engine oil, relate to different systems within the vehicle. Spark plugs are part of the ignition system, responsible for igniting the air-fuel mixture in the engine; they do not affect the air conditioning system. Worn brake pads pertain to the braking system and have no relevance to A/C functionality. Similarly, while dirty engine oil can impact engine performance and longevity, it is unrelated to how the air conditioning system operates. Thus, the correct answer highlights the specific components and conditions that can directly cause issues in the air