input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Vasopressin antagonist acts on which pa of the nephron?   (A) Proximal convoluted tubule   (B) Distal convoluted tubule   (C) Coical collecting tubule   (D) Medullary collecting duct
output: ['(D) Medullary collecting duct <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Proximal convoluted tubule  (B) Distal convoluted tubule  (C) Coical collecting tubule  (D) Medullary collecting duct <> possible answers', '  Vasopressin antagonist acts on which pa of the nephron? <> context']