input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Metformin causes I severe, sometimes life-threatening side effect of lactic acidosis. All of the following factors increase the risk of lactic acidosis except:   (A) Advanced age   (B) Smoking   (C) Liver dysfunction   (D) Renal failure
output: ['(B) Smoking <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Advanced age  (B) Smoking  (C) Liver dysfunction  (D) Renal failure <> possible answers', '  Metformin causes I severe, sometimes life-threatening side effect of lactic acidosis. All of the following factors increase the risk of lactic acidosis except: <> context']