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': 'Complete Rx of intussception is indicated by \nSelect and explain. \nA. Free passage of barium in the terminal ileum, B. Passage of feces and flatus along with barium, C. Improvement of clinical condition, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]