A Racehorse Cannot Stand on One Leg,but When It Runs

A racehorse cannot stand on one leg,but when it runs it rarely has more than one leg on the ground.Why is a running horse more stable than a standing one?

A) Its internal organs act like a gyroscope.
B) Its legs tilt so the hooves fall in line with its center of gravity.
C) It uses its neck for balance the way a tightrope walker uses a pole.
D) Its momentum gives it stability.