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: Biochemistry
[{'content': 'Patient with deficiency of Vitamin K, pre surgical\ntest required is \nSelect and explain. \nA. PT time, B. Bleeding time, C. Clotting time, D. bleeding index', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]