This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anaesthetic equipments, Subject name: Anaesthesia
[{'content': 'The most impoant constituent in soda lime for reabsorption of CO2 in a closed circuit \nSelect and explain. \nA. Sodium hydroxide, B. Barium hydroxide, C. Calcium hydroxide, D. Potassium hydroxide', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Sodalime is most common Co2 absorbant . Indicators added to sodalime changes the color of sodalime . It contains 94% Ca(OH)2 , 5%NaOH,1% KOH.', 'role': 'assistant'}]