This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Plastic Surgery and Skin Lesions, Subject name: Surgery
[{'content': 'Treatment of choice for melanoma is: \nSelect and explain. \nA. Chemotherapy, B. Surgical excision, C. Radiotherapy, D. Surgery and chemotherapy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Treatment Surgical excision with Sentinel lymph node biopsy Margins to be taken depends on the tumor thickness and depth of invasion * < 1mm thickness - 1 cm margin * 1-4 mm thickness - 2cm margin * > 4mm thickness - 2-3 cm margin Malignant Melanoma is a radio resistant tumor *', 'role': 'assistant'}]