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
Temporary hardness of water is due to the presence of following salts of calcium and magnesium: 
Select and explain. 
A. Bicarbonates, B. Sulphates, C. Chlorides, D. Nitrates
A: Bicarbonates
Answer: A: Bicarbonates 
Explanation: None