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: Surgery
[{'content': 'Most common origin of melanoma is from \nSelect and explain. \nA. Junctional melanocytes, B. Epidermal cells, C. Basal cells, D. Follicular cells', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Sabiston (16/e) writes -\n"Melanoma is a neoplastic disorder produced by malignant transformation of the normal melanocytes. Melanocytes are the cells responsible for the production of the pigment melanin.\nDuring the first trimester of fetal life precursor melanocytes arise in the neural crest. As the fetus develops, these cells migrate to areas such as the skin, meninges, mucous membranes, upper esophagus and eyes.\nIn each of the these locations, melanocytes have demonstrated a potential for malignant transformation, but the site most commonly associated with melanocytic transformation is the skin, where melanocytes reside at the dermal/epidermal junction".', 'role': 'assistant'}]