The following are multiple choice questions (with answers) about medical knowledge.   **Question:** Access cavity shape in mandibular 1st molar with 4 canals   (A) Trapezoidal   (B) Round   (C) Oval   (D) Triangular
['(A) Trapezoidal <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Trapezoidal \n (B) Round \n (C) Oval \n (D) Triangular <> possible answers', '  Access cavity shape in mandibular 1st molar with 4 canals <> context@']