The chemical equation which represents the modification of bicarbonates in hard water by the use of a zeolite softener is
a) Ca(HCO3)2 + Na2Z = CaZ + 2NaHCO3
b) CaZ + 2NaCl = Na2Z + CaCl
c) MgSO4 + Na2Z = MgZ + Na2SO4
d) Ca(HCO3)2 + Na2Z = CaZ + NaHCO3
e) MgZ + 2NaCl = Na2 + MgCl2
Answer: A