Given below are two statements: Statement I: The number of pairs, from the following, in which both the ions are coloured in aqueous solution is 3. […

Given below are two statements: Statement I: The number of pairs, from the following, in which both the ions are coloured in aqueous solution is $\displaystyle 3$ . $\displaystyle \left[\mathrm{Sc}^{3+}, \mathrm{Ti}^{3+}\right],\left[\mathrm{Mn}^{2+}, \mathrm{Cr}^{2+}\right],\left[\mathrm{Cu}^{2+}, \mathrm{Zn}^{2+}\right]$ and $\displaystyle \left[\mathrm{Ni}^{2+}, \mathrm{Ti}^{4+}\right]$ Statement II: $\displaystyle \mathrm{Th}^{4+}$ is the strongest reducing agent among $\displaystyle \mathrm{Th}^{4+}, \mathrm{Ce}^{4+}, \mathrm{Gd}^{3+}$ and $\displaystyle \mathrm{Eu}^{2+}$.In the light of the above statements, choose the correct answer from the options given below