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 following is not true of platelet transfusion - \nSelect and explain. \nA. Useful in ITP, B. Used in DIC, C. Effective for 9-10 days, D. Effect decrease with repeated usage', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]