What term describes the boundary where two plates move away from each other?

• A. Spreading ridge
• B. Subduction zone
• C. Transform boundary
• D. Collision zone

Answer: (A)

When two tectonic plates move away from each other, the boundary is divergent. At oceanic divergent boundaries, magma rises to fill the gap and creates new crust as it cools. The surface feature that marks this process is a spreading ridge, a long, elevated belt that forms the mid-ocean ridge system and drives seafloor spreading.

This makes spreading ridge the best term here because it directly describes both the boundary type (divergent) and the characteristic feature produced there. Subduction zones occur where plates come together and one sinks beneath another, not where they separate. Transform boundaries involve plates sliding horizontally past each other. Collision zones refer to convergent boundaries where crust is crushed together, not pulled apart.