Final answer:
The most abundant gas released by mafic magma is water vapor (C)
Step-by-step explanation:
The most abundant gas released by mafic magma is water vapor (C). Today, we see that water vapor, carbon dioxide (CO₂), sulfur dioxide (SO₂), and other gases are released from deeper within the Earth through the action of volcanoes. However, much of this gas is recycled material that has been subducted through plate tectonics.