Fact 1: An automobile engine transforms chemical energy into mechanical energy.

Fact 2: Cars have V-8 engines and are functional.

Given the two facts above, answer the question "What converts chemical energy into mechanical energy?" with the following options: 
- rocks
 - batteries
 - water vapor
 - monkeys
 - cats
 - a car
 - cows
 - rockets


 

      a car   