What Can Cause Water to Separate from a Water-Bearing Basaltic

Multiple Choice

What can cause water to separate from a water-bearing basaltic magma to drive an eruption?

A) Injection of dry rhyolite magma into the basalt magma chamber from below can cause water to separate.
B) A decrease in pressure as the magma rises can cause water to separate.
C) Water streaming up into the magma chamber from the Earth's mantle can cause this.
D) Once water gets into a basalt magma, it can't separate.
E) Basalt magmas only erupt as lava flows; water is irrelevant.