input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Unpaired structures in the brain:   (A) Basilar artery   (B) Vertebral artery   (C) Middle cerebral artery   (D) Anterior cerebral artery
output: ['(A) Basilar artery <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Basilar artery  (B) Vertebral artery  (C) Middle cerebral artery  (D) Anterior cerebral artery <> possible answers', '  Unpaired structures in the brain: <> context']