Part of the Reason That Precipitation Is More Acidic in the Northeastern

Part of the reason that precipitation is more acidic in the northeastern United States is:

A) local pollution is compounded by pollution drifting in from upwind population centers.
B) many factories are using shorter chimney stacks.
C) the local vegetation influences the acidity of rainwater forming in the region.
D) water vapor contributed by the Great Lakes is naturally more acidic.