Multiple choice Which of the following options does not cause acid rain? Carbon dioxide Methane Chlorofluorocarbon (CFC) Nitrogen oxide Reveal answer Fill a bubble to check yourself B Correct answer Explanation Methane is an odorless, colourless, flammable gas, with chemical formula CH4. It is the major constituent of natural gas, that is used as a fuel and is an important source of energy. It does not cause acid rain.