The Florida Keys are an archipelago (chain of islands) off the southern coast of Florida. The Keys are made of mainly softer materials like limestone and fossilized coral. The Hawaiian Islands are also an archipelago, but are made of much harder igneous rock. Which of the following explains why the Hawaiian Islands are made of such different materials than the Florida Keys? A.
Coral does not grow near the Hawaiian Islands.

B.
The Hawaiian Islands were built mostly by people.

C.
Igneous rocks are only found in the Hawaiian Islands.

D.
The Hawaiian Islands formed through volcanic eruptions.