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': 'Foetal hea sound can be seen by transvaginal doppler from : \nSelect and explain. \nA. 5th week, B. 10th week, C. 8th week, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 5th week', 'role': 'assistant'}]