This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: miscellaneous, Subject name: Pathology
[{'content': 'The most common histologic type of carcinoma of the oral cavity is \nSelect and explain. \nA. Adenocarcinoma, B. Clear cell carcinoma, C. Large cell undifferentiated carcinoma, D. Squamous cell carcinoma', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Carcinoma of the oral cavity accounts for approximately 5% of all human malignancies. More than 90% of oral carcinomas are of the squamous cell type. Precursor lesions include leukoplakia (dysplastic leukoplakia) and erythroplasia, with transformation rates of approximately 15 and 50%, respectively. Oral carcinoma is more common in males. Smoking, tobacco chewing, chronic irritation, heat exposure, and irradiation are all thought to contribute to carcinogenesis. The lower lip is the most common site, followed by the floor of the mouth, the anterior tongue, the palate, and the posterior tongue. Prognosis varies according to site but is best for lesions of the lip and worst for lesions in the floor of the mouth.', 'role': 'assistant'}]