Human activities have caused both acid rain and a global increase in temperature, or global warming. How are these two effects--acid rains and global warming--related to each other? A. Acid rain is a side effect of global warming at the local level B. Acid rain is a side effect of efforts to reduce global warming C. Both acid rain and global warming are caused by the burning of fossil fuels D. Both acid rain and global warming are caused by increased levels of carbon dioxide in the atmosphere
