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: Gynaecology & Obstetrics
[{'content': 'Male infeility occurs if the sperm count is less than : \nSelect and explain. \nA. 100 mill / ml, B. 75 mill / ml, C. 50 mill / ml, D. 20 mill / ml', 'role': 'user'}, {'content': 'Answer: D \nExplanation: 20 mill / ml', 'role': 'assistant'}]