The main way water gets into a subduction zone is by:

A) heating of the overlying continental crust
B) a decrease in pressure that causes melting
C) rain associated with eruptions in the island arc
D) seawater introduced into oceanic crust at the mid-ocean ridge, prior to subduction
E) all of these

Subduction Zone

A region at convergent plate boundaries where one tectonic plate moves under another into the mantle, often causing earthquakes and volcanic activity.

Seawater

The saltwater that makes up the oceans and seas covering more than 70% of the Earth's surface, comprising a complex solution of various salts and minerals.

Mid-Ocean Ridge

A subaquatic chain of mountains created by the movement of tectonic plates, leading to the formation of new ocean floor.