What is the main source of atmospheric emissions of mercury? 

A)  rocks and soils 
B)  coal burning 
C)  gold mining 
D)  volcanoes

Coal burning is considered the main source of atmospheric emissions of mercury. When coal is burned to produce electricity or for industrial purposes, mercury is released into the atmosphere. This mercury can then enter waterways and accumulate in fish and other organisms, posing a risk to human and wildlife health. While other sources, such as gold mining and volcanoes, do contribute to atmospheric emissions of mercury, they are not considered to be the main sources.