This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neoplasia, Subject name: Surgery
[{'content': 'Which melanoma is malignant \nSelect and explain. \nA. Juctional, B. Blue nevus, C. Intra dermal, D. None', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (Junctional) (43- Bailys love 20th)A. Malignant melanoma may ariseA. de - novo in apparently normal skinB. In a preexisting prigmented nevus Malignant changes in a benign nevus occurs only in the JUNCTIONAL or compound variety. Pure dermal naevus is safe', 'role': 'assistant'}]