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': 'Which of the following emits gamma radiations only? \nSelect and explain. \nA. Strontium 89, B. Technetium 99m, C. Phosphorus 32, D. Tin 117m', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Radionuclides react with hydroxyapatite and the pattern of uptake is seen on the bone scan. Strontium-89, Samarium-153, Phosphorus -32, Rhenium-186, Tin -117m emit beta particles with a mean range between 0.2 to 3 mm, minimising toxicity to the surrounding tissues.\nTechnetium 99m emits gamma radiations and is used as a diagnostic tool in medical sciences.', 'role': 'assistant'}]