<prompt> Factor IX deficiency results in increasedPTPTTBTTT  <response>: 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 