The following are multiple choice questions (with answers) about medical knowledge.   **Question:** 2nd optimal landmark for termination of cleaning, shaping and obturation is   (A) Apical constriction   (B) Cementodentinal junction   (C) Major diameter   (D) None of the above
['(A) Apical constriction <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Apical constriction \n (B) Cementodentinal junction \n (C) Major diameter \n (D) None of the above <> possible answers', '  2nd optimal landmark for termination of cleaning, shaping and obturation is <> context@']