Where are volcanoes most likely to form in the Ring of Fire?

• A. In the deep ocean near trenches
• B. At transform boundaries
• C. Along subduction zones where an oceanic plate is forced under a continental plate
• D. At the poles

Answer: (C)

Volcanoes in the Ring of Fire form mainly where subduction occurs—the oceanic plate sinks beneath another plate. As the sinking slab descends, it releases water into the surrounding mantle, which lowers the melting point and generates magma. This magma then rises into the overlying plate, feeding volcanic eruptions and creating a line of volcanoes parallel to the boundary. That’s why the best answer points to where an oceanic plate is forced under another plate, a hallmark of subduction zones. Transform boundaries produce little magma, and being simply near a trench in the deep ocean or at the poles doesn’t establish the conditions needed for widespread volcanic activity.