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 of the following feature may be used to differentiate hemophilia A from von Willebrand disease \nSelect and explain. \nA. Bleeding time, B. Prothrombin time, C. Paial thromboplastin time, D. Factor VIII levels', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Answer is A (Bleeding time) : Bleeding time is prolonged in von Willebrand disease, but normal in Hemophilia A Both conditions present with decreased levels of factor VIII normal PT and elevated PTT and hence these features cannot be used to differentiate between hemophilia A and von Willebrand disease. Features of VWF and differences with Haemophilia A Feature Hemophilia A Von Willebrand Disease Inheritance Sex linked Autosomal (Most common is A.dominant) Factor VIIIc Decreased Decreased VWF Normal Decreased Ristocetin cofactor Normal Decreased Common Presentation Features of clotting disorder Skin/Mucosal bleeding -- Hemahrosis ++ Features of bleeding disorder +- clotting disorder Skin/Mucosal bleeding + Hemohrosis+ Bleeding Time Normal Prolonged APTT Prolonged Prolonged (may be normal) PT Normal Normal Thrombin Time Normal Normal Fibrinogen Normal Normal Platelet aggregation in Response to Ristocetin Normal Decreased', 'role': 'assistant'}]