Which one of the following complexes will have $\Delta_0 = 0$ and $\mu = 5.96 \ B.M.?$

Which of the following complexes will have the lowest value of $\Delta_0$?

Low spin complex of $d^6$ cation in an octahedral field will have the following energy:
($\Delta_o =$ crystal field splitting energy in an octahedral field,$P =$ Electron pairing energy)

The configurations of the complexes of manganese $A$ and $B$ respectively are $t_{2g}^3 e_g^1$ and $t_{2g}^4 e_g^0$. Then $A$ and $B$ are:

Number of complexes with an even number of electrons in $t_{2g}$ orbitals is -
$[Fe(H_2O)_6]^{2+}, [Co(H_2O)_6]^{2+}, [Co(H_2O)_6]^{3+}, [Cu(H_2O)_6]^{2+}, [Cr(H_2O)_6]^{2+}$

Given below are two statements:
Statement $I$: Presence of a large number of unpaired electrons in transition metal atoms results in higher enthalpies of their atomisation.
Statement $II$: $d_{xy} = d_{xz} = d_{yz} < d_{x^2-y^2} = d_{z^2}$ and $d_{x^2-y^2} < d_{xy} = d_{xz} = d_{yz}$ are the $d$-orbital splittings in $[Fe(H_2O)_6]^{3+}$ and $[Ni(Cl)_4]^{2-}$ complex ions respectively.
In the light of the above statements, choose the correct answer from the options given below: