Which boundary is commonly associated with subduction zones and volcanic activity?

• A. Convergent Boundary
• B. Divergent Boundary
• C. Transform Boundary
• D. Oceanic-Continental Boundary.

Answer: (D)

Subduction and volcanic activity happen at convergent plate boundaries, where two tectonic plates collide and one plate sinks beneath the other. When an oceanic plate subducts under a continental plate, it carries water down into the mantle. This water lowers the melting point of rocks in the overlying mantle, generating magma that rises to the surface and feeds volcanoes, often forming a volcanic arc along the edge of the overriding plate. An oceanic-continental boundary is a common real-world example of this setup, but subduction also occurs at other convergent boundaries (like oceanic beneath oceanic), so the defining feature is the convergent boundary itself. Thus, the boundary most closely associated with subduction zones and volcanic activity is the convergent boundary.