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: Dental
[{'content': 'Main disadvantage of glass bead sterilizer: \nSelect and explain. \nA. Technique sensitive, B. Only glass instruments can be sterilized, C. Only small instruments can be sterilized, D. None of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The hottest part of glass bead sterilizer is along its outer rim and the temperature is lowest in\xa0the centre of surface layer of salt.\xa0\nTo sterilize an instrument properly, one should immerse at least a\xa0 “quarter-inch" below the salt\xa0surface and in peripheral area of the sterilizer.\xa0\nThe main disadvantage of glass bead sterilizer is that only small instruments can be sterilized.\xa0\xa0\nTemp ⇒ 425°F - 475F°F\xa0 for 5 sec.', 'role': 'assistant'}]