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: Social & Preventive Medicine
[{'content': 'According to WHO criteria, all are true in a normal person except \nSelect and explain. \nA. Sperm count >20 million, B. Aggressive forward motility in >25%, C. Normal morphology in >15% (strict criteria), D. Volume >1 ml', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]