The following are multiple choice questions (with answers) about medical knowledge.   **Question:** In cephalometric radiography, the distance between the subject and the source of X-ray is   (A) 2 feet   (B) 48 inches   (C) 4.8 metres   (D) 5 feet
['(D) 5 feet <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) 2 feet \n (B) 48 inches \n (C) 4.8 metres \n (D) 5 feet <> possible answers', '  In cephalometric radiography, the distance between the subject and the source of X-ray is <> context@']