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': 'The coagulation profile in a 13-year old girl with Menorrhagia having Von Willebrands disease is: \nSelect and explain. \nA. Isolated prolonged PTT with a normal PT, B. Isolated prolonged PT with a normal PTT, C. Prolongation of both PT and PTT, D. Prolongation of thrombin time', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Answer is A (Isolated prolonged PTT with a normal PT) Von Willebrand disease is characterized by prolonged bleeding time and a prolonged PTT. The prothrombin time is normal.', 'role': 'assistant'}]