During the 1960s Sudbury,Ontario's Prosperity Was Tempered by Environmental Problems

During the 1960s Sudbury,Ontario's prosperity was tempered by environmental problems.What was the problem?

A) Methyl isocynate released as a byproduct resulted in a massive fish and animal kills,and endangered human health.
B) Cyanide and heavy metals entering the biosphere made local crops toxic to humans.
C) Sulfur dioxide emissions killed much of the local vegetation creating a huge barren area.
D) Petroleum waste,and floating trash caused portions of Nephawin Lake to catch fire.