Avolcanic island arc is formed when a. two oceanic plates converge and form an subduction zone. b. volcanic activity occurs within the plate. c. three convergent plates form an intraplate gap. d. a continental plate meets a oceanic plate and form an subduction zone.

The correct answer is - D. A continental plate meets an oceanic plate and form a subduction zone.

When a continental and oceanic tectonic plates collide, the heavier, denser, oceanic plate starts to subduct under the lighter, less dense continental tectonic plate. From the place of subduction, the extreme temperature, pressure, and magma are able to push through to the surface. As they reach the surface they start to produce volcanic activity, and as the surface is lifting, the volcanoes emerge above the sea level, thus creating a chain of volcanic arc islands.