This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Clinical Presentation and Physiology, Subject name: Surgery
[{'content': 'Sentinel lymph node is defined as - \nSelect and explain. \nA. Primary LN draining tumor, B. LN which is first excised during MRM, C. LN nearest to tumor, D. None', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Primary LN draining tumor", 'role': 'assistant'}]