The following are multiple choice questions (with answers) about medical knowledge.   **Question:** The fourth root canal if present in a maxillary 1st molar is usually present in:   (A) Mesiolingual root   (B) Mesiobuccal   (C) Palatal root   (D) Distal root
['(B) Mesiobuccal <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Mesiolingual root \n (B) Mesiobuccal \n (C) Palatal root \n (D) Distal root <> possible answers', '  The fourth root canal if present in a maxillary 1st molar\nis usually present in: <> context@']