Low spin complex of $d^6$ cation in an octahedral field will have the following energy:
($\Delta_o =$ crystal field splitting energy in an octahedral field,$P =$ Electron pairing energy)

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $[CoCl(NH_3)_5]^{2+}$ absorbs at a lower wavelength of light with respect to $[Co(NH_3)_5(H_2O)]^{3+}$.
Reason $R$: It is because the wavelength of the light absorbed depends on the oxidation state of the metal ion.
In the light of the above statements,choose the correct answer from the options given below:

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

List-$I$ (Electronic configuration of tetrahedral metal ion)	List-$II$ (Crystal Field Stabilization Energy $(\Delta_t)$)
$A$. $d^2$	$I$. $-0.6$
$B$. $d^4$	$II$. $-0.8$
$C$. $d^6$	$III$. $-1.2$
$D$. $d^8$	$IV$. $-0.4$

The correct order of the wavelength of light absorbed by the following complexes is,
$A. [Co(NH_3)_6]^{3+}$
$B. [Co(CN)_6]^{3-}$
$C. [Cu(H_2O)_4]^{2+}$
$D. [Ti(H_2O)_6]^{3+}$
Choose the correct answer from the options given below:

In potassium ferrocyanide,there are $..........$ pairs of electrons in the $t_{2g}$ set of orbitals.

The order of energy absorbed,which is responsible for the color of the following complexes,is: