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
Which of the following is the site of malignant transformation of melanocytes in melanoma? 
Select and explain. 
A. Junctional melanocytes, B. Epidermal cells, C. Basal cells, D. Follicular cells
A: Junctional melanocytes
Answer: A: Junctional melanocytes 
Explanation: Melanoma results from the malignant transformation of melanocytes usually located at the dermal-epidermal junction. Melanoma confined to the epidermis is termed melanoma in situ, which is theoretically 100% curable. With time, the melanoma invades veically into the dermis where it can metastasize to the regional lymph nodes and/or other distant visceral organ systems the lymphatic or vascular systems. Ref: Ludgate M.W., Wang T.S. (2009). Chapter 100. Skin Cancer. In J.B. Halter, J.G. Ouslander, M.E. Tinetti, S. Studenski, K.P. High, S. Asthana (Eds), Hazzard's Geriatric Medicine and Gerontology, 6e.