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': 'CAT was invented by– \nSelect and explain. \nA. Hounsfield, B. Roentgen, C. Cormack, D. Tesla', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A new method of forming images from X-rays (i.e. CT/CAT) was developed and introduced into clinical use by a British physicist Godfrey Hounsfield in 1972.', 'role': 'assistant'}]