Which components are part of an EFI system?

The correct choice encompasses key components that define an Electronic Fuel Injection (EFI) system. The fuel tank stores the gasoline, while the fuel filter is critical for maintaining the quality of the fuel by removing contaminants before they reach the engine. The ECU (Engine Control Unit) is the brain of the EFI system; it processes data from various sensors and makes real-time decisions to optimize fuel delivery and engine performance. These sensors monitor parameters such as air intake temperature, engine temperature, and throttle position, which are essential for calculating the correct fuel-air mixture. Finally, the fuel injectors are responsible for delivering the precise amount of fuel into the combustion chamber at the correct time, which is crucial for efficient engine operation and reduced emissions.

The other options do not provide a complete representation of the essential components of an EFI system. While some include components related to fuel delivery or engine operation, they lack the necessary combination of the ECU and sensors, which are vital for the operational integrity of an EFI system. Hence, option C stands out as the most accurate reflection of an EFI system's components.