Which of the following would most likely be found in the oesophagus of a patient suffering from gastroesophageal reflux disease?

Gastroesophageal reflux disease (GERD) is a chronic condition in which the lower oesophageal sphincter allows gastric acids to backflow into the oesophagus, causing heartburn. Pepsin of gastric juice is most likely to be regurgitated into the oesophagus. Trypsin, chymotrypsin and carboxypeptidase are the components of pancreatic juice released into the duodenum. Backflow of these into the stomach is prevented by pyloric sphincter.