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': 'Balanced stone is dental stone: \nSelect and explain. \nA. Which undergoes rapid expansion, B. In which, accelerators or retarders have been added according to need, C. In which, amount of water of hydration is controlled, D. In which, the crystals are all of uniform size', 'role': 'user'}, {'content': 'Answer: B \nExplanation: A stone with a setting time established by the addition of proper quantities of both accelerator\xa0and retarder is called ‘balanced stone’.\xa0\nTypical accelerators are potassium sulfate and potassium sodium tartrate (Rochelle Salts).\nTypical retarders are sodium citrate and sodium tetraborate decahydrate (Borax).\nManappalil pg-313', 'role': 'assistant'}]