In basic medium the amount of `Ni^(2+)` in a solution can be estimated with the dimethylglyoxime reagent. The correct statement(s) about the reaction and the produt is(are)

Options

A. in ammoniacal solution `Ni^(2+)` salts gives cherry-red precipitate of nickel(II) dimethylglyoximate
B. two dimethylglyoximate units are bounde to one `Ni^(2+)`
C. in the complex two dimethylglyoximate units are hydrogen bounded to each other
D. each dimethylglyoximate unit forms a six =membered chelate ring with `Ni^(2+)`