Identify the ion (hydrated in solution) which is not correctly matched with its spin only magnetic moment (in BM) given in brackets

• Correct answer
  A

  $\mathrm{Cr}^{3+}(4.90)$
• B

  $\mathrm{Cu}^{2+}(1.73)$
• C

  $\mathrm{Co}^{3+}(4.90)$
• D

  $\mathrm{Fe}^{2+}(4.90)$

Hence, the correct answer is option: 'A'.