Use reasoning to answer the following question. These belong to the class of creature that were the first true tetrapods:
Options:
- (A) millipede
- (B) crabs
- (C) four limbs
- (D) bullfrogs
- (E) gastropod
- (F) a fish
- (G) warm-blooded
- (H) insects
Amphibians are the first true tetrapods, or vertebrates with four limbs. Bullfrogs eat other amphibians. Bullfrogs are of the class of creatures that were the first true tetrapods.
So, the answer is (D).