This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
[{'content': 'Commercially available digital imaging includes: \nSelect and explain. \nA. RVG, B. Flash dent, C. Sense-a–ray, D. All of the above.', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Digital imaging (commercially available):\xa0\n• RVG\xa0\n• Flash dent\xa0\n• Sense-a–ray', 'role': 'assistant'}]