Please answer the following question by reasoning step-by-step.
What is an example of a tetrapod vertebrate?\nOptions:\n- (A) genus\n- (B) Leeuwenhoek\n- (C) a fish\n- (D) crocodile\n- (E) animals\n- (F) four limbs\n- (G) warm-blooded\n- (H) graptolites

(D)
Reptiles are a class of tetrapod vertebrates that produce amniotic eggs.

Crocodiles, snakes, and lizards are all types of reptiles.

Crocodiles are a type of tetrapod vertebrates that make amniotic eggs.

.

Therefore, the answer is (D)