This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Stomach & Duodenum, Subject name: Surgery
[{'content': 'Most common cause of upper gastrointestinal tract bleeding is: \nSelect and explain. \nA. Esophageal varices, B. Peptic ulcer, C. Gastritis, D. Mallory-Weiss tear', 'role': 'user'}, {'content': "Answer: B \nExplanation: Peptic ulcer is the most common cause of upper GI bleeding, present in one-half to two-third of patient with upper GI bleeding. Only 10-15% of'Heavy' drinkers develop alcoholic cirrhosis (leading to esophageal varices) Mallory - Weiss Syndrome Characterized by longitudinal paial tear (only mucosa + sub mucosa involved) Most common site is cardia (just below GE junction.) More common in Alcoholic males", 'role': 'assistant'}]