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': 'The etching of intact enamel with phosphoric acid produces: \nSelect and explain. \nA. an increases in surface area, B. a decrease in surface area, C. An increase in chemical bonding capabilities, D. a decrease in chemical bonding capabilities', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]