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': "Theodore Croll 1986 is associated with: \nSelect and explain. \nA. Use of 18% hydrochloric acid and pumice - microabrasion, B. Use of 12 fluted bur to remove the defects, C. Bleaching techniques, D. Dakin's solution", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]