How does a rocket engine's efficiency relate to nozzle throat area and expansion ratio?

How does a rocket engine's efficiency relate to nozzle throat area and expansion ratio?

• A. Efficiency depends on energy conversion; nozzle throat area and expansion ratio influence exhaust velocity and thrust performance.
• B. Efficiency is independent of nozzle geometry
• C. Efficiency only depends on fuel type
• D. Efficiency is inversely proportional to expansion ratio regardless of nozzle design

Answer: (A)