What are the conditions that will lead to a failure in the intake and fuel systems? (Choose the correct answer)

When assessing the intake and fuel systems of a vehicle, fuel leakage is a critical issue that can lead to system failure. Fuel leakage signifies that fuel is not contained within the appropriate system boundaries, which can result in inadequate fuel delivery to the engine. This compromised integrity can create safety hazards, such as the risk of a fire, and it can also lead to engine performance problems due to insufficient fuel reaching the combustion chamber.

In contrast, overfilling the fuel tank can cause fuel vapor issues and could potentially trigger a fuel evaporation emission failure, but it does not directly relate to the integrity or functionality of the intake and fuel systems themselves. A broken fuel gauge may indicate that the tank is low or full, but it does not impact the actual delivery or function of the fuel system. Engine performance issues could stem from various factors and may not necessarily indicate a problem with the intake and fuel systems specifically. Thus, fuel leakage stands out as a clear condition that would lead to a failure in the intake and fuel systems.