The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Which of the following appliances is not used for slow maxillary expansion?   (A) Jack screw   (B) Coffin spring   (C) Quad helix appliance   (D) Hyrax appliance
['(D) Hyrax appliance <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Jack screw \n (B) Coffin spring \n (C) Quad helix appliance \n (D) Hyrax appliance <> possible answers', '  Which of the following appliances is not used for slow maxillary expansion? <> context@']