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': 'TB can be easily differentiated from squamous cell carcinoma by: \nSelect and explain. \nA. Acid positive with ziehl neelsen stain, B. Primary lesion occur on tongue, C. Biopsy can confirm the diagnosis, D. Direct smear examination', 'role': 'user'}, {'content': 'Answer: C \nExplanation: There is general agreement that lesions of the oral mucosa are seldom primary, but rather secondary to pulmonary disease. Lesions of secondary tuberculosis may occur at any site on the oral mucous membrane,\xa0but the tongue is most commonly affected,\xa0followed by the palate, lips,\xa0buccal mucosa,\xa0gingiva and frenula.\nThe diagnosis of active infection must be confirmed by the demonstration of the organisms by special microbial\xa0stains and culture of the infected tissue or sputum. The presence of acid-fast bacilli (AFB)\xa0in sputum.\nTB\xa0can be easily differentiated from squamous cell carcinoma by biopsy. Biopsy can confirm the diagnosis.', 'role': 'assistant'}]