Correct Answer - D
`V(Z=23):[Ar]^(18)4s^(2)3d^(3)`
`V^(3+) : [Ar]^(18)3d^(2)`
`V^(3+)` undergoes `d^(2)sp^(3)` hybridisation, involving 3d, 4s and 4p-orbitals, to accommodate six lone pairs form six `NH_(3)` molecules. Thus , outer orbital hybridisation is involved