$[Co(NH_3)_5SO_4]Br$ and $[Co(NH_3)_5Br]SO_4$ are a pair of isomers.

Match the List-$I$ with List-$II$:

List-$I$ (Complex ion)	List-$II$ (Calculated spin only magnetic moment $(BM)$)
$A$. $[Cr(H_2O)_6]^{2+}$	$I$. $3.87$
$B$. $[Co(H_2O)_6]^{2+}$	$II$. $5.92$
$C$. $[Cu(H_2O)_6]^{2+}$	$III$. $4.90$
$D$. $[Mn(H_2O)_6]^{2+}$	$IV$. $1.73$

Choose the correct answer from the options given below:

Identify the pair of complexes that have the same magnetic moment (spin-only value).

The compounds $[Cr(H_2O)_6]Cl_3$,$[Cr(H_2O)_5Cl]Cl_2 \cdot H_2O$ and $[Cr(H_2O)_4Cl_2]Cl \cdot 2H_2O$ exhibit:

The $d-$electron configurations of $Cr^{2+}, Mn^{2+}, Fe^{2+}$ and $Co^{2+}$ are $d^4, d^5, d^6$ and $d^7$ respectively. Which one of the following will exhibit minimum paramagnetic behaviour?
(At. nos. $Cr = 24, Mn = 25, Fe = 26, Co = 27$)

Which of the following has the largest number of isomers?