Use reasoning to lead to the answer of the following question:
What forms in shallow tropical water?\nOptions:\n- (A) ocean\n- (B) romance\n- (C) bushes\n- (D) ferns\n- (E) reefs\n- (F) bamboo\n- (G) fossils\n- (H) snorkelling

(E)
Corals form large colonies in shallow tropical water.

Huge colonies of hard corals form coral reefs.

Reefs form in shallow tropical water.

.

So, the answer is (E)