Forces affect motions in living and nonliving things. In a human, swallowed food moves down the esophagus into the stomach, even if the human is upside down doing a handstand. Which force moves food through the esophagus into the stomach? a:Frictional force in the esophagus moves food through the esophagus.

b:Gravitational force pulls food through the esophagus.

c:Magnetic force in the stomach pulls food through the esophagus into the stomach.

d:Push force from contractions of the esophagus moves food through the esophagus.