Which of the following statements best describes the relationship between the natural resources of the united states and canada and the environmental issues facing both countries?
a.
both countries produce large amounts of iron, lead, copper, gold and silver.
b.
environmental problems such as air and water pollution are causing natural resources like fossil fuels and lumber sources to disappear.
c.
the natural resources directly cause all of the environmental problems.
d.
the methods used to extract many of the natural resources cause air and water pollution.

select the best answer from the choices provided.

a
b
c
d