Multiple choice Acid rain occurs when _______ is/are released by industries. sulphur dioxide nitrogen oxide carbon dioxide both 1 and 2 Reveal answer Fill a bubble to check yourself D Correct answer Explanation Acid rain forms when sulfur dioxide (SO2) and nitrogen oxides (NOx) from industrial emissions react with water vapor in the atmosphere. Carbon dioxide contributes to general rain acidity but is not the primary cause of acid rain phenomenon.