Answer:
A) volcanic
Explanation:
Oceanic island are formed where their is volcanic eruption on the sea floor . This island rises above the sea water and can experience active volcanoes overtime.
This island are formed when the oceanic plates collides with the more active continental crust. Example of this island is the Aleutian Island. The oceanic crust been denser, subduct under the more active and less dense continental crust. This subduction brings about crustal migration of molten magma from the earth interior .
This molten magma due to pressure may erupt through the vents on the sea floor to form oceanic islands . Generally, this eruption build up to form new crust and invariably form a volcano on the seafloor. This is why most oceanic islands are volcanic in nature . And this island are also called volcanic Island.
