The bahamas were created by built-up layers of volcanic soil tectonic activity that thrust mountains up from the ocean floor built-up remains of once-living creatures called coral polyps repeated volcanic eruptions

B. Tectonic activity that thrust mountains up from the ocean floor 

Tectonic activity that thrust mountains up from the ocean. floor because volcanoes come from the center of the earth and when the tectonic plates move it causes some of the lava from the inside of the earth to emerge and come to the surface where the ocean is and forms into an island (s).

The answer to the question is moraine