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': 'Diagnostic criteria of Hodgkin&;s disease are A/E - \nSelect and explain. \nA. RS cells, B. Atypical cells in background, C. Sclerosing pattern, D. CD 30 present', 'role': 'user'}, {'content': 'Answer: B \nExplanation: <p>RS cells are invariably accompanied by a variable number of atypical Hodgkin cells which are believed to be precursor RS cells but are not considered diagnostic of HD.</p><p>Reference :Harsh mohan textbook of pathology sixth edition pg no 370.</p>', 'role': 'assistant'}]