Consider the coordination compounds $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+},\left[\mathrm{CoCl}\left(\mathrm{NH}_3\right)_5\right]^{2+},\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)\left(\mathrm{NH}_3\right)_5\right]^{3+}$, and $\left[\mathrm{Co}(\mathrm{CN})_6\right]^{3-}$, denoted respectively, by $\mathbf{P}, \mathbf{Q}, \mathbf{R}$, and $\mathbf{S}$. The correct order of wavelengths of light absorbed by the compounds is

• A

  $\mathbf{Q} \gt \mathbf{P} \gt \mathbf{R} \gt \mathbf{S}$
• Correct answer
  B

  $\mathbf{Q} \gt \mathbf{R} \gt \mathbf{P} \gt \mathbf{S}$
• C

  $\mathbf{S} \gt \mathbf{R} \gt \mathbf{Q} \gt \mathbf{P}$
• D

  $\mathbf{S} \gt \mathbf{R} \gt \mathbf{P} \gt \mathbf{Q}$

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