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: Forensic Medicine
[{'content': 'Motile spermatozoa found in wet mount of vaginal secretions are indicative of intercourse within the past: Karnataka 09; LIP 09; MAHE 11 \nSelect and explain. \nA. 6 h, B. 12 h, C. 24 h, D. 48 h', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. 12 h', 'role': 'assistant'}]