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: Radiology
[{'content': 'One advantage of digital radiography is: \nSelect and explain. \nA. All the teeth can be in a single film, B. Highly economical, C. The radiographic images are obtained immediately, D. Pulpal vitality can be accurately assessed', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]