The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Cavity varnish is used for:   (A) To reduce thermal conductivity   (B) To reduce the permeability of acid into dentinal tubules   (C) Action as an obtundant   (D) All of the above
['(B) To reduce the permeability of acid into dentinal tubules <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) To reduce thermal conductivity \n (B) To reduce the permeability of acid into dentinal tubules \n (C) Action as an obtundant \n (D) All of the above <> possible answers', '  Cavity varnish is used for: <> context@']