I'll give you a question, please answer with step-by-step reasoning process.
Mussels have what?\nOptions:\n- (A) seaweed\n- (B) arms\n- (C) Energy\n- (D) a shell\n- (E) warmth\n- (F) bacteria\n- (G) Length\n- (H) legs

(D)
Most mollusks have shells.

Mussels are bivalve mollusks.

Mussels have shells.

.

So, the answer is (D)