Final answer:
The correct answer is Continuous fuel injection.
Step-by-step explanation:
The correct answer is Continuous fuel injection. Throttle-body injection, port fuel injection, and central fuel injection are all types of electronic fuel injection systems used in automotive engines. Throttle-body injection is the simplest and cheapest system, where fuel is injected directly into the throttle body.
Port fuel injection injects fuel into the intake ports just before the intake valves, improving fuel atomization. Central fuel injection, also known as throttle body injection, uses a single point injector mounted in the throttle body to supply fuel to all the cylinders. On the other hand, continuous fuel injection is a type of mechanical fuel injection system, not electronic.