Using the Choices Below, Select the Statement That Best Explains

Using the choices below, select the statement that best explains how dissolved gases drive volcanic eruptions.

A) As the magma rises, gas bubbles contract, fragmenting the material and expelling it from the vent.
B) As the magma rises, gases reduce silicate mineral chains by breaking silicon-oxygen bonds; the result is an explosion.
C) Confining pressure decreases on a rising magma, allowing gas bubbles to expand and fracture the magma.This process further decreases pressure on the magma and will result in an explosive event.
D) Decreases in confining pressure result in decreasing viscosity of the magma, allowing the magma to ooze from the volcano.