The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Etching time in teeth with fluorosis   (A) 10-15 sec   (B) 15-30 sec   (C) 60-90 sec   (D) Can’t be etched
['(C) 60-90 sec <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) 10-15 sec \n (B) 15-30 sec \n (C) 60-90 sec \n (D) Can’t be etched <> possible answers', '  Etching time in teeth with fluorosis <> context@']