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: Pathology
[{'content': "Scleroderma involves: \nSelect and explain. \nA. Tightening of oraL mucosa and periodontal involvement, B. Multiple palmar keratosis, C. Raynaud's phenomenon, D. All of the above", 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]