Which of the following statements about the impact of surface and underground mining of minerals is correct?
a. underground mining is just as disruptive to the surface as strip and open-pit mining.
b. precipitation seeping through piles of waste rock taken from strip and open pit mines can dissolve toxic metals and other chemicals that can then flow into nearby rivers and streams.
c. strip and open-pit mining disturbs large areas of earth’s surface.
d. all of the above