Which substance should have its atmospheric concentrations reduced in
order to return acid rain to rain's normal ph?
a. cfcs
b. sulfur
c. water
d. phosphorous

The correct option is B, Sulfur.

Explanation:

Acid rain can be described as a form of precipitation that has increased amounts of acidic ions in it. The acid rain can cause severe damage to the plants and animals. The main compounds that lead to accumulation of acid in atmosphere are sulfur dioxide and nitrogen dioxide.

In order to prevent acid rain, the concentration of sulfur should be reduced from the environment. Atmospheric pollutants such as sulfur dioxide and nitrogen dioxide should be reduced.