Some statements are given below $-$
$(a)$ Coordination compounds $[Pt(NH_3)_3(NCS)]$ and $[Pt(NH_3)_3(SCN)]$ are examples of linkage isomerism.
$(b)$ In the coordination compound $K_4[Ni(CN)_4]$, the oxidation state of nickel is zero.
$(c)$ The hybridization, shape and magnetic moment of $K_3[Cu(CN)_4]$ are respectively $dsp^2$, square planar, $1.73 \ B.M.$
$(d)$ $[Cr(NCS)(NH_3)_5][ZnCl_4]$ exhibits only linkage isomerism.

• A
  only $a, b, c$ are correct
• B
  only $a, b$ are correct
• C
  only $b, c, d$ are correct
• D
  All are correct