JEE Advanced 2017 Chemistry question

Addition of excess aqueous ammonia to a pink coloured aqueous solution of (**X**) and gives an octahedral complex **Y** in the presence of air. In aqueous solution, complex **Y** behaves 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., whereas it is zero for complex **Y**. Among the following options, which statement(s) is(are) correct?

• (A)Addition of silver nitrate to **Y** gives only two equivalents of silver chloride
• (B)The hybridization of the central metal ion in **Y** is Correct
• (C)**Z** is a tetrahedral complexCorrect
• (D)When **X** and **Z** are in equilibrium at 0°C, the colour of the solution is pinkCorrect