Answer:
sulfur oxide is the correct answer.
Step-by-step explanation:
Acid rain is created when water vapor in the atmosphere absorbs sulfur oxide.
sulfur oxides are produced by burning fossil fuels, from vehicles and oil industry and other types of industry.
When sulfur reacts with oxygen it forms sulfur dioxides, and these sulfur dioxides when react with water vapor in the atmosphere sulphuric acid is formed and these sulphuric acids when further react with oxygen then rainwater becomes acidic.