Answer:
b. Continental-oceanic
Step-by-step explanation:
The Earth's crust has been divided into a series of plates. These plates move at a different rate or speed in different directions.
These plates are divided by the boundary between them which are of three types: convergent, transform and divergent.
The convergent boundaries are the one which moves toward each other and the based on the crust they are of three types: continent-continent, ocean-ocean and ocean-continent.
In ocean-continent boundaries, the oceanic plate is denser compared to the continental plate is lighter as a result of which during the process of subduction the oceanic plate sinks beneath the continental plate towards the mantle and melts.
Thus, Option-B is the correct answer.