Gastrointestinal stimulants help treat gastroesophageal reflux disease by

a. increasing the amount of hydrochloric acid produced during digestion.
b. increasing the rate of stomach emptying to inhibit the flow of materials back into the esophagus.
c. blocking the dopamine neurotransmitter in gastrointestinal nerves and in the vomiting center in the brain.
d. inhibiting smooth muscle contractions in order to interrupt peristalsis.