Soaps do not work in hard water containing calcium and magnesium ions because

Options

A. `Ca^(2+) and Mg^(2+)` ions form insoluble calcium and magnesium salts in the form of scum
B. `Na^(+) and K^(+)` present in soap react with `Ca^(2+) and Mg^(+)` and hinder cleansing process
C. a large amount of soap is to be used in presence of `Ca^(+) and Mg^(+)`
D. scum formed by combination of `Na^(+), Ca^(2+) and Mg^(2+)` stick to the cloth and are not removed on agitation

Answer

A