Which of the Following Statements Best Defines Gastroesophageal Reflux (GER)

Which of the following statements best defines gastroesophageal reflux (GER) ?

A) Stomach contents are returned into the lower esophagus through the lower esophageal sphincter.
B) Formula or other intake is routed to an outpouching in the esophagus and then squeezed out and back to the esophagus.
C) The stomach is too small, and it can't handle the large amount of formula that some caregivers give in one feeding.
D) The esophagus is too narrow in its entire length, and it shoots back up and out the mouth.