C, Hawaiian islands is your answer.
As seen even today, land are created when an underground volcano spews out hot rocks that come in contact with water. When land is created on the top, volcanoes that form that are active can continue to expand the island through magma coming in contact with the ocean, which creates more land when cooled down. Cooled Magma also is rich in nutrients, which, in the right season, can yield high potential growth in vegetations.
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