This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oral Cavity, Subject name: Surgery
[{'content': 'Second primary tumor of head and neck is most commonly seen in malignancy of: \nSelect and explain. \nA. Oral cavity, B. Larynx, C. Hypopharynx, D. Paranasal sinuses', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Oral cavityRef: Bailey and Love Page 712* Field cancerization:# This is a phenomenon in which the risk factors like smoking, HPV etc., stimulate the growth of similar cancer in other sites with same predisposing factors.# Such Phenomenon is common in oral cavity cancer. They are highly prone to Lung cancer and other head and neck cancers due to field cancerization.', 'role': 'assistant'}]