What has acid deposition been linked to? 

A)  excessive levels of soil carbon 
B)  the contamination of insects by highly toxic methylmercury 
C)  the weakening of trees such that they become more susceptible to other types of damage 
D)  reduced nutrient uptake by tree leaves

Acid Deposition

The falling of acids and acid-forming compounds from the atmosphere to the Earth's surface, often as rain, snow, or dust, with harmful environmental effects.

Methylmercury

A highly toxic form of mercury that bioaccumulates in fish and shellfish, posing health risks to humans and wildlife.

Nutrient Uptake

The process by which organisms absorb nutrients from the environment to support their growth and metabolism.