Which type of environmental pollution would not be the direct result of the human use of fossil fuels? a) the expansion of landfills with too much garbage to recycle. b) the contamination of rivers and groundwater from automotive runoff. c) the exxon valdez oil spill in alaska that killed a lot of wildlife and fouled the coastlines. d) the present greenhouse effect, caused by the accumulation of large amounts of carbon dioxide in the atmosphere from smog.