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
Which is the main component of soda-lime in closed circuit 
Select and explain. 
A. Sodium hydroxide, B. Barium hydroxide, C. Calcium hydroxide, D. Potassium hydroxide
C: Calcium hydroxide
Answer: C: Calcium hydroxide 
Explanation: Sodalime constitutes a mixture of 95% Ca(OH)2, 5% NaOH and 1%KOH.