Trees have woody stems covered with what?\nOptions:\n- (A) heat energy\n- (B) thin skin\n- (C) protective skin\n- (D) skinny cells\n- (E) white skin\n- (F) Chlorophyll\n- (G) Organic compounds\n- (H) looseness
Step-by-step reasoning process below:
(C)
Trees have woody stems covered with bark.

On the outside is a protective skin of bark made mainly of cork.

Trees have woody stems covered with protective skin.

.

So, the answer is (C)