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: Pathology
[{'content': 'Factor IX deficiency results in increased \nSelect and explain. \nA. PT, B. PTT, C. BT, D. TT', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'B' i.e., PTT (Paial thromboplastin time) Paial thromboplastin time (PTT) :It tests the intrinsic and common coagulation pathways. So, a prolonged PTT canresults from deficiency of factor V, VIII (factor VIIIc, Von willebrand factor), IX, X, XI, XII, prothrombin or fibrinogen.Prothrombin time (PT) :It tests the extrinsic and common coagulation pathways. So, a prolonged PT can results from deficiency of factor V, VII, X, prothrombin or fibrinogen.Thus in common coagulation pathway defect both PT and PTT are elevated.Activated clotting time (clotting time) :It also tests the intrinsic and common coagulation system. So it is prolonged in deficiency of same factors as for prolonged PTT", 'role': 'assistant'}]