What Tectonic Event in the Western U

Multiple Choice

What tectonic event in the western U.S. caused magmatism and deformation to move farther into the continent during the late Mesozoic and early Cenozoic Laramide Orogeny?

A) the continent overran a hot spot
B) the continent overran the East Pacific Rise
C) continental extension stretched the continent to twice its original width
D) an oceanic plate subducted at a low angle beneath the continent