A student is studying the esophagus. Which statement made by this student to a faculty member is a correct one? "The smooth muscle layers provide the peristaltic movements needed to move food along the length of the esophagus.""The smooth muscle layers provide the peristaltic movements needed to move food along the length of the esophagus." "The upper esophageal sphincter passes through an opening, or hiatus, in the diaphragm.""The upper esophageal sphincter passes through an opening, or hiatus, in the diaphragm." "The gastroesophageal sphincter keeps air from entering the esophagus and stomach during breathing.""The gastroesophageal sphincter keeps air from entering the esophagus and stomach during breathing." "The lower sphincter, known as the pharyngoesophageal sphincter, lies just above the area where the esophagus joins the stomach.""The lower sphincter, known as the pharyngoesophageal sphincter, lies just above the area where the esophagus joins the stomach