Fact 1: Grasses supply most of the food consumed by people worldwide.

Fact 2: Because food contains energy.

Given the two facts above, answer the question "What contains most of the energy used by people worldwided?" with the following options: 
- heat
 - Light
 - coal
 - grasses
 - Cooking
 - glucose
 - A computer
 - gasoline


 

    grasses     