Which of the following statements is correct?

$1\,L, 0.02\,M$ solution of $[Co(NH_3)_5SO_4]Br$ is mixed with $1\,L, 0.02\,M$ solution of $[Co(NH_3)_5Br]SO_4$. The resulting solution is divided into two equal parts $(X)$ and treated with excess $AgNO_3$ solution and $BaCl_2$ solution respectively as shown below:
$1\,L$ Solution $(X) + AgNO_3$ solution (excess) $\rightarrow Y$
$1\,L$ Solution $(X) + BaCl_2$ solution (excess) $\rightarrow Z$
The number of moles of $Y$ and $Z$ respectively are:

For the reaction $K_4[Fe(CN)_6] \xrightarrow{\text{oxidation}} Fe^{3+} + CO_2 + NO_3^-$,which of the following statements is incorrect?

The complex ion $[Co(en)_2Br_2]^+$ has two optical isomers. Their correct configurations are:

Among the statements $(a)-(d)$,the incorrect ones are:
$(a)$ Octahedral $Co(III)$ complexes with strong field ligands have very high magnetic moments.
$(b)$ When $\Delta_{0} < P$,the $d-$electron configuration of $Co(III)$ in an octahedral complex is $t_{2g}^{4} e_{g}^{2}$.
$(c)$ Wavelength of light absorbed by $[Co(en)_{3}]^{3+}$ is lower than that of $[CoF_{6}]^{3-}$.
$(d)$ If the $\Delta_{0}$ for an octahedral complex of $Co(III)$ is $18,000 \ cm^{-1}$,the $\Delta_{t}$ for its tetrahedral complex with the same ligand will be $16,000 \ cm^{-1}$.

Which of the following statements is not correct?