This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CT SCAN, Subject name: Radiology
[{'content': 'Slip ring technology is used in \nSelect and explain. \nA. First generation CT, B. Ultrasound, C. MRI, D. Spiral CT', 'role': 'user'}, {'content': 'Answer: D \nExplanation: A Slip ring is an electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure. A slip ring can be used in any electromechanical system that requires rotation while transmitting power.', 'role': 'assistant'}]