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.
I would increase the amount of organic matter in my soil by adding compost, aged animal manures, peat moss, and cover crops. This is for improved soil structure that will allow plants to grow on easily. Adjusting the soil fertility will make the farmland fertile.