Among the following complexes, the one which shows Zero crystal field stabilisation energy (CFSE) is:

CFSE is zero for $d^0$, $d^{10}$, and high-spin $d^5$ configurations in octahedral fields.$[\text{Fe}({\text{H}}_2\text{O}{)}_6{]}^{3+}$: ${\text{Fe}}^{3+}$ is a $d^5$ system. ${\text{H}}_2\text{O}$ is a weak field ligand, so it forms a high-spin complex.Distribution: $t_{2g}^3{e}_g^2$.$\text{CFSE}=[-0.4\times 3+0.6\times 2]{\Delta }_0=[-1.2+1.2]{\Delta }_0=0$.Thus, $[\text{Fe}({\text{H}}_2\text{O}{)}_6{]}^{3+}$ has zero CFSE.