Which of the Following Statements About Continental Drift Is True

Which of the following statements about continental drift is true?

A) When it was proposed, the idea received almost immediate acceptance.
B) Continents move because as magma rises, it exerts tremendous pressure on the plates that float on top of it.
C) Deep rift valleys have been generated from the same process that causes continental drift.
D) Both a and b
E) Both b and c