CFSE for [CoCl₆]^-4 is 18000cm^-1, CFSE for [CoCl₄]^-2 will be

CFSE for [CoCl₆]^-4 is 18000cm^-1, CFSE for [CoCl₄]^-2 will be
A. 6000cm^-1
B. 16000cm^-1
C. 8000cm^-1
D. 18000cm^-1

[NEET Odisha 2019]

[CoCl₆]^-4 is octahedral complex while [CoCl₄]^-2 is tetrahedral complex.
We now that
Δ_tet = 4/9Δ_oct
putting the value of Δ_oct = 18000cm^-1 we get-
Δ_tet = (4/9) x 18000cm^-1 = 8000cm^-1
Thus, the CFSE for [CoCl₄]^-2 will be 8000cm^-1
So, the correct option is C.