The following are multiple choice questions (with answers) about medical knowledge.   **Question:** All of the following affects bur efficiency except:   (A) Spiral angle   (B) Head length and diameter   (C) Neck diameter   (D) Crosscut
['(B) Head length and diameter <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) Spiral angle \n (B) Head length and diameter \n (C) Neck diameter \n (D) Crosscut <> possible answers', '  All of the following affects bur efficiency except: <> context@']