A Researcher Has Been Studying Lichens in His Hometown

Multiple Choice

A researcher has been studying lichens in his hometown. Since he began his study, he has noticed several lichens dying in the vicinity of a new factory. What is MOST likely causing the decrease in lichen populations?

A) the diversion of water sources to the factory (i.e., lichens are drying out)
B) an increase in air temperature, which is the result of CO₂ emissions from the factory
C) the blocking of sun by the factory (i.e., the lichens aren't getting enough sunlight)
D) an increase in industrial pollutants in the area