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: Anaesthesia
[{'content': 'The substance is soda lime that acts as catalyst is \nSelect and explain. \nA. Sodium hydroxide, B. Potassium hydroxide, C. Calcium hydroxide, D. Silica', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Potassium hydroxide acts as catalyst for generation of sodium carbonate.', 'role': 'assistant'}]