Why does the west coast of the United States experience volcanic activity and earthquakes while the east coast does not?

A) Because the west coast does not lie on a plate boundary, while the east coast does.


B) Because the west coast lies on a thinner area of continental crust than the east coast does.


C) Because the west coast has more cities than the east coast does.


D) Because the west coast lies on a plate boundary, while the east coast does not.