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: ENT
[{'content': 'Metastasis of carcinoma buccal mucosa goes to \nSelect and explain. \nA. Regional lymph node, B. Liver, C. Heart, D. Brain', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The spread of carcinoma of buccal mucosa \n\nBuccal carcinoma spread locally and to regional lymph nodes.\n\n1) Local spread: - From its site of origin, the lesion may spread deeply involving submucosa → muscle → Subcutaneous fat → skin. Involvement of buccinator muscle or anterior masseter causes trismus.\n2) Lymphatic spread: - Nodal involvement occurs in about 50% of cases. Submandibular and later the upper jugular nodes may get involved. Upper jugular nodes may also be involved, directly skipping the submandibular group.', 'role': 'assistant'}]