The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Branchial fistula is persistent of:   (A) 1st branchial cleft.   (B) 1st branchial arch.   (C) 2nd branchial cleft.   (D) 2nd branchial arch.
['(C) 2nd branchial cleft. <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) 1st branchial cleft. \n (B) 1st branchial arch. \n (C) 2nd branchial cleft. \n (D) 2nd branchial arch. <> possible answers', '  Branchial fistula is persistent of: <> context@']