Methane burns in oxygen to yield carbon dioxide and water. The chemical formula for this reaction is:
a) CH₄ + 2O₂ → CO₂ + 2H₂O
b) CH₄ + O₂ → CO₂ + H₂O
c) CH₄ + 3O₂ → CO₂ + 2H₂O
d) CH₄ + O₂ → CO₂ + 2H₂O