Examine the map above showing the acidity of rainfall across the USA. How might the distribution of the acidity be explained?

A.

The acidity of the rain decreases over the western half of the country because there is less rainfall there.

B.

The acidity of the rain increases over the eastern half of the country because evaporated water from the Atlantic Ocean affects the air's pH.

C.

The acidity of the rain is directly related to the amount of forested land in each region.

D.

The acidity of the rain increases over highly populated, highly industrial regions because of the accumulation of waste products in the air.