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: Anatomy
[{'content': 'Which of the following does not drain into the sub \nmental lymph nodes? \nSelect and explain. \nA. Upper lip, B. Tip of tongue, C. Floor of mouth, D. Central lower lip', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]