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: Surgery
[{'content': 'Trichobezoar is - \nSelect and explain. \nA. Hair ball in stomach in psychiatric patient, B. Tumours of stomach, C. TB of bowel, D. Collection of worms in stomach', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]