Given below are two statements: Statement 1: The number of pairs, from the following, in which both the ions are coloured in aqueous solution is 3 . $$ \left[\mathrm{Sc}^{3+}, \mathrm{Ti}^{3+}\right],\left[\mathrm{Mn}^{2+}, \mathrm{Cr}^{2+}\right],\left[\mathrm{Cu}^{2+}, \mathrm{Zn}^{2+}\right] \text { and }\left[\mathrm{Ni}^{2+}, \mathrm{Ti}^{4+}\right] $$ Statement II: $\mathrm{Th}^{4+}$ is the strongest reducing agent among $\mathrm{Th}^{4+}, \mathrm{Ce}^{4+}, \mathrm{Gd}^{3+}$ and $\mathrm{Eu}^{2+}$. In the light of the above statements, choose the correct answer from the options given below