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: ENT
[{'content': 'In carcinoma of lower lip secondaries are seen in: \nSelect and explain. \nA. Submandibular LN, B. Preauricular LN, C. Mediastinal LN, D. Supraclavicular LN', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (a) submandibular LN(Ref. Cummings, 6th ed., 1364)Nodal spread from carcinoma lower lip involves submental and submandibular lymph nodes (level 1).', 'role': 'assistant'}]