input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** About acid etching of dentin all are true, except:   (A) It removes smear layer   (B) It expose collagen   (C) It opens dentinal tubules   (D) It increase surface tension
output: ['(D) It increase surface tension <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) It removes smear layer  (B) It expose collagen  (C) It opens dentinal tubules  (D) It increase surface tension <> possible answers', '  About acid etching of dentin all are true, except: <> context']