What is the difference between a turbofan and a turbojet engine?

What is the difference between a turbofan and a turbojet engine?

• A. A turbofan relies primarily on exhaust jet thrust with less bypass air.
• B. A turbofan uses a large bypass fan to boost thrust.
• C. A turbofan has a large bypass fan that creates additional thrust with higher efficiency and lower noise.
• D. A turbojet is always quieter.

Answer: (C)