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: Dental
[{'content': 'Stippling is absent in: \nSelect and explain. \nA. Infants only, B. Older men, C. Children, D. Both infants and old', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]