Addition of excess aqueous ammonia to a pink coloured aqueous solution of `MCl_(2).6H_(2)O( X)` and `NH_(4)Cl` gives an octahedral complex Y in the presence as `1:3` electrolyte. The reaction of X with excess HCl at room temperature results in the formation of a blue coloured complex Z. The calculated spin only magnetic moment of X and Z is 3.87 B.M., where it is zero for complex Y.
Among the following options, which statemens(s) is (are) correct
A. The hybridization of the central metal ion in Y is `d^(2)sp^(3)`
B. Additoin of silver nitrate to Y gives only two equivalents of silver chloride
C. When X and Z are in equilibrium of `0^(@)C` ,the coloure of the solution in pink
D. Z is a tetrahedral complex
