Given below are two statements :

Statement I : The number of pairs among $\left[\mathrm{Ti}^{4+}, \mathrm{V}^{2+}\right],\left[\mathrm{V}^{2+}, \mathrm{Mn}^{2+}\right],\left[\mathrm{Mn}^{2+}, \mathrm{Fe}^{3+}\right]$ and $\left[\mathrm{V}^{2+}, \mathrm{Cr}^{2+}\right]$ in which both ions are coloured is 3 .

Statement II : The number of pairs among $\left[\mathrm{La}^{3+}, \mathrm{Yb}^{2+}\right],\left[\mathrm{Lu}^{3+}, \mathrm{Ce}^{4+}\right]$ and $\left[\mathrm{Ac}^{3+}, \mathrm{Lr}^{3+}\right]$ ions in which both are diamagnetic is 3 .

In the light of the above statements, choose the correct from the options given below :

Given below are two statements for catalytic properties of transition metals.

Statement I : First row transition metals which act as catalyst utilise their 3d electrons only for formation of bonds between reactant molecules and atoms on the surface of catalyst.

Statement II : There is increase in the concentration of reactants on the surface of catalyst which strengthens the bonds in reacting molecules.

In the light of the above statements, choose the correct answer from the options given below :

The correct order of first $\left(\Delta_i \mathrm{H}_1\right)$ and second $\left(\Delta_i \mathrm{H}_2\right)$ ionisation enthalpy values of Cr and Mn are :

A. $\Delta_i \mathrm{H}_1: \mathrm{Cr}>\mathrm{Mn}$

B. $\Delta_i \mathrm{H}_2: \mathrm{Cr}>\mathrm{Mn}$

C. $\Delta_i \mathrm{H}_1: \mathrm{Mn}>\mathrm{Cr}$

D. $\Delta_i \mathrm{H}_2: \mathrm{Mn}>\mathrm{Cr}$

Choose the correct answer from the options given below :

The correct statements among the following are :

A. Basic vanadium oxide is used in the manufacture of $\mathrm{H}_2 \mathrm{SO}_4$.

B. The spin-only magnetic moment value of the transition metal halide employed in Ziegler-Natta polymerization is 2.84 BM .

C. The p-block metal compound employed in Ziegler-Natta polymerization has the metal in +3 oxidation state.

D. The number of electrons present in the outer most ' d ' orbital of metal halide employed in Wacker process is 8.

Choose the correct answer from the options given below :