This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, 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: <p>Reed Sternberg cells in all types of Hodgkin&;s diseases, except in lymphocytic prdominance type,express immunoreactivity for CD 15 & CD 30. RS cells in lymphocytic predominance type are negative for both CD 15 & CD 30, but positive for CD 20.</p><p>Reference : Harsh mohan textbook of pathology 6th edition pg no370</p>', 'role': 'assistant'}]