This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hematology, Subject name: Pediatrics
[{'content': 'The coagulation profile in a 13 year old girl with menorrhagia having von Willebrand&;s 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: In vonwillebrand disease aPTT will be prolonged and PT will be normal. Reference: GHAI Essential pediatrics, 8th edition', 'role': 'assistant'}]