Multiple choice

Burning of which of the following fuels produces the least amount of carbon dioxide per unit of energy?

  1. Coal

  2. Oil

  3. Wood

  4. Natural gas

  5. All of these produce the same amount of carbon dioxide

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

Natural gas is the purest fuel, which burns completely in air to produce large amount of energy and no smoke is produced.