Task: Question Answering
Input (English): Acid rain can damage limestone buildings and marble statues. It can also harm organisms living in ponds and other ecosystems. Which pollutant in the atmosphere causes most of the acid rain?  
 (A) fluorocarbons from aerosol spray cans (B) nitrous oxide from volcanic eruptions (C) sulfur dioxide from burning fossil fuels (D) soil particles from the use of farm equipment
Output (English): C