$$\text{CrCl}_3 \cdot x\text{NH}_3$$ can exist as an octahedral complex (P). 0.1 molal aqueous solution of this complex P shows a depression in freezing point of $$0.558^\circ\text{C}$$. The molecular formula of the complex P, given that $$K_f$$ for water is 1.86 K kg per $$mol^-1$$ and assuming 100% ionization of the complex, is

A

$$[\text{Cr(NH}_3)_6]\text{Cl}_3$$

B

$$[\text{Cr(NH}_3)_5\text{Cl}]\text{Cl}_2$$

C

$$[\text{Cr(NH}_3)_4\text{Cl}_2]\text{Cl}$$

D

$$[\text{Cr(NH}_3)_3\text{Cl}_3]$$