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: Pathology
[{'content': 'Sentinel lymph node biopsy is used for ? \nSelect and explain. \nA. Melanoma, B. Basal cell carcinoma, C. Squamous cell carcionoma, D. Thyroid carcinoma', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Melanoma Sentinel lymph node biopsy is used for breast carcinoma and melanoma.", 'role': 'assistant'}]