I'll give you a question, please answer with step-by-step reasoning process.
Where do corals form large colonies?\nOptions:\n- (A) Mars\n- (B) new World\n- (C) Sediment\n- (D) shoreline\n- (E) environment\n- (F) Absorb light\n- (G) loose soil\n- (H) polyps

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

Water is shallow at the shore with gradual deepening.

Corals form large colonies at the shoreline.

.

The answer: (D)