Which of the following items must be checked for leaks during inspection?

In the context of vehicle inspections, a key aspect is ensuring that all potential sources of leaks are thoroughly examined to guarantee safety and performance. The fuel system is critical because any leaks can lead to hazardous conditions, including fire risks and emissions issues.

While it's true that both the oil filter and exhaust system also require inspections for leaks, the fuel system is particularly emphasized because of the safety implications tied directly to leaking fuel. A proper inspection should encompass all potential leak sources as they can pose significant risks to the vehicle's operation and the environment.

Therefore, the inclusion of the fuel system as a focus area during inspections is essential. Inspections should ideally cover all parts of the vehicle mentioned in the question, but understanding the emphasis on the fuel system highlights the importance of addressing specific safety concerns associated with leakage in that area.