This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood Physiology, Subject name: Physiology
[{'content': 'Prothrombin Time (PT) detects deficiency of all the following clotting factors EXCEPT \nSelect and explain. \nA. II, B. V, C. VII, D. VIII', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The time required for clotting to occur is called the prothrombin time (PT). Normal PT = 15-20 seconds. Prolonged PT suggests the possibility of deficiency of factors II (prothrombin), V, VII and X. Prothrombin level is low in vitamin K deficiency and various liver and biliary diseases.', 'role': 'assistant'}]