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': 'Which is abnormal in classic hemorrhagic disease of newborn ? \nSelect and explain. \nA. Platelet count, B. Thrombin time, C. Fibrinogen level, D. APTT', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Thrombin time', 'role': 'assistant'}]