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: Medicine
[{'content': 'Which is most likely to be increased in Vit K deficiency: \nSelect and explain. \nA. P.T.T., B. P.T., C. Platelet count, D. Fibrinogen time', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Answer is B (P.T.): Although PT and PTT both will he affected PT is the single best answer as explained below. Therefore both intrinsic & extrinsic mechanisms of the coagulation cascade are affected. (Refer previous questions) PT & PTT both will be prolonged. However, factor VII has sho t1/2 & so PT is the first to be prolonged (even in mild vit. K deficiency) Later, factors II, IX & X will also fall, causing PTT to be prolonged. PT is thus the better choice out of PT and PTT', 'role': 'assistant'}]