This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CLL & CML, Subject name: Medicine
[{'content': 'Which has worst prognosis in CLL? \nSelect and explain. \nA. 11q Deletion, B. 12q Trisomy, C. 17p Deletion, D. 13q Deletion', 'role': 'user'}, {'content': 'Answer: C \nExplanation: 13q deletion : Indolent course ; good prognosis Trisomy 12 : Intermediate prognosis 11q deletion : Poor prognosis 17p deletion : Poorest prognosis', 'role': 'assistant'}]