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': 'Urinary tract infection exists when the bacterial count in 1 ml. of midstream specimen of urine is - \nSelect and explain. \nA. 100, B. 1000, C. 10\n4, D. 10\n5\n or over', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]