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': 'Carcinoma of buccal mucosa commonly drain to the following lymph nodes sites - \nSelect and explain. \nA. Submental, B. Submandibular, C. Supraclavicular, D. Cervical', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Nodal involvement occurs in 50% cases of tumors of buccal mucosa.\nMost common lymph node involved : Submandibular lymph nodes.', 'role': 'assistant'}]