The reaction involved during the removal of temporary hardness of water is:
A. `2CaCl_(2) + (NaPO_(3))_(6) to Na_(2)(Ca_(2)(PO_(3))_(6)) + 4NaCl`
B. `CaCl_(2) + Na_(2)CO_(3) to CaCO_(3) darr+ 2NaCl`
C. `MgSO_(4)+Na_(2) Al_(2) Si_(2) O_(8) xH_(2)O to MgAl_(2) SiO_(7)xH_(2)O + Na_(2)SO_(4)`
D. `Ca(HCO_(3))_(2) to CaCO_(3) + H_(2) O + CO_(2) darr`
