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': 'Radium emits which of the following radiations: \nSelect and explain. \nA. Alpha rays, B. Beta rays, C. Gamma rays, D. All', 'role': 'user'}, {'content': 'Answer: D \nExplanation: A i.e. a rays; B i.e. b-rays; C i.e. g -rays', 'role': 'assistant'}]