Final answer:
Deinonychus walked on three toes of each hind foot, using its first, third, and fourth toes for locomotion while the second toe's large claw was held off the ground.
Step-by-step explanation:
Deinonychus, an agile predator from the Cretaceous period, is notably recognized for its distinctive anatomy and gait. The question regarding how many toes Deinonychus used to walk on each hind foot can be answered by looking at paleontological evidence. This dinosaur is well-known for its large, sickle-shaped claw on the second toe of each foot, which it held retracted off the ground. Therefore, Deinonychus must have walked on three toes of each hind foot, which are its first, third, and fourth toes. The correct answer to the question is B. three.