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': 'Paralytic ileus is caused by - \nSelect and explain. \nA. Peritonitis, B. Hyperkalemia, C. Acute intestinal obstruction, D. Head injury', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Peritonitis", 'role': 'assistant'}]