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': "Classical markers for Hodgkin's disease is - \nSelect and explain. \nA. CD 15 and CD 30, B. CD 15 and CD 22, C. CD 15 and CD 20, D. CD 20 and CD 30", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]