input: The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Excision of the submandibular gland for calculus or tumours is done by incision below angle of the jaw. Special care should be taken to avoid which nerve?   (A) Ansa cervicalis   (B) Mandibular branch of facial nerve   (C) Posterior auricular nerve   (D) Submandibular ganglion
output: ['(B) Mandibular branch of facial nerve <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Ansa cervicalis  (B) Mandibular branch of facial nerve  (C) Posterior auricular nerve  (D) Submandibular ganglion <> possible answers', '  Excision of the submandibular gland for calculus or tumours is done by incision below angle of the jaw. Special care should be taken to avoid which nerve? <> context']