Mount Shasta and Mount Lassen in the Far Northeastern Part

Mount Shasta and Mount Lassen in the far northeastern part of California,were formed by what process?

A) The transformative motion of the North American plate against the Pacific plate.
B) The divergence of the North American plate and the Juan de Fuca plate.
C) The subduction of the Juan de Fuca plate beneath the North American plate.
D) The convergence of the North American Plate against the Pacific plate.