Multiple choice general knowledge math & puzzles

Which is the odd one out?

  1. Propulsion

  2. Fuel

  3. Gravity

  4. Combustion

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Propulsion, fuel, and combustion are all related to the mechanics of engines and movement. Gravity is a fundamental natural force of attraction, making it the odd one out in this context.