All food can be broken down to 3 basic components. they are:

a. carbohydrates, fats and proteins

b. solids, liquids and gases

c. candy, candy canes and candy corn

d. fruits, vegetables and milk

I think it's A. Carbohydrates, fats, and proteins.  

because natural gas is colorless, odorless, and tasteless, distributors add mercaptan (a chemical that smells like sulfur) to give natural gas a distinct unpleasant odor (it smells like rotten eggs). they locate the types of rock that are likely to contain natural gas deposits.