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': 'Hemophilia A has following except - \nSelect and explain. \nA. ↓ VIII factor, B. ↑PTT, C. ↑PT, D. Normal BT', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Hemophila A\n\nHemophilia A is due to deficiency of factor VIII.\nHemophilia A is inherited as an X-linked recessive trait.\nFactor VIII is an intrinsic pathway component required for activation of factor X.\nClinical manifestations are due to defect in coagulation system : -\n\n\n\nLarge post-traumatic ecchymoses or hematoma.\n\n\nProlonged bleeding after a laceration or any form of surgical procedure.\n\n\nBleeding into weight-bearing joints.\n\n\n\nPetechiae are characteristically absent (in contrast to platelet dysfunction where bleeding occurs from small vessels of the skin and mucous membrane, e.g., petechiae).\n\nLaboratory findings\n↑ PTT\nNormal PT\nNormal BT\nNormal platelet counts\n\nRemember\n\nHemophilia B (Christmas disease) is due to deficiency of factor IX.\nHemophilia B has clinical features and laboratory findings similar to hemophilia A.', 'role': 'assistant'}]