Permanent hardness of water can be removed by
(A) Addition of soda ash to it
(B) Treating it with zeolites
(C) Passing it through sodium hexametaphosphate
(D) All (A), (B), and (C)
(A) Addition of soda ash to it
(B) Treating it with zeolites
(C) Passing it through sodium hexametaphosphate
(D) All (A), (B), and (C)