Which of the Following Best Describes Melting of the Mantle

Which of the following best describes melting of the mantle at subduction zones that leads to island arc volcanos?

A) Heat is carried downward with the subducting plate and melts the mantle above the downgoing plate.
B) Water released from the subducting plate decreases the melting temperature in the mantle above the downgoing plate to generate magmas from the overlying mantle wedge.
C) The subducting plate is heated as it is carried to depth and the subducted oceanic crust melts.
D) The subducted plate subsides into the mantle and allows magma from the lower mantle magma ocean to rise toward the surface.