This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Peptic ulceration occurs at all the following sites except - 
Select and explain. 
A. Lesser curvature, B. First part of duodenum, C. Lower end of esophagus, D. Stoma of gastric portion of gastrojejunostomy
D: Stoma of gastric portion of gastrojejunostomy
Answer: D: Stoma of gastric portion of gastrojejunostomy 
Explanation: Peptic ulcer

Ulcers are defined histologically as a breach in the mucosa of the alimentary tract that extends through the muscular mucosa into the submucosa or deep.
Peptic ulcers are chronic, most often solitary lesions that occur in any portion of the gastrointestinal tract exposed to the aggressive action of acid/peptic juice.

Peptic ulcers located in the following sites, in order of decreasing frequency :

Duodenum, 1st portion
Stomach, usually antrum
At the gastro - esophageal junction in the setting of gastroesophageal reflux or Barrett's esophagus.
Within the margins of a gastrojejunostomy.
In the duodenum, stomach or jejunum of patients with Zollinger -Ellison Syndrome.
Within or adjacent to Meckel's diverticulum that contains ectopic gastric mucosa.