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: Skin
[{'content': 'Earliest feature of Tuberous sclerosis is: \nSelect and explain. \nA. Angiofibroma, B. Shagreen patch, C. Ash leaf spot, D. Neurofibroma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ash leaf spot', 'role': 'assistant'}]