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: Pathology
[{'content': "Which of the following features cannot be used to differentiate between Hodgkin's and Non Hodgkin's Lymphoma ? \nSelect and explain. \nA. Extranodal involvement, B. Spread contiguity, C. Painless lymphadenopathy, D. Localisation to a particular group of lymph nodes", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Hodgkin lymphoma, like NHL, usually manifests as painless lymphadenopathy.\xa0 Although a definitive distinction from\xa0NHL\xa0can be made only by examination of a\xa0tissue biopsy,\xa0 several clinical features favor the diagnosis of\xa0Hodgkin lymphoma.\xa0After the diagnosis is established, staging is used to guide therapy and determine prognosis.', 'role': 'assistant'}]