In following pairs, the one in which both transition metal ions are colourless is:
\( \mathrm{Sc^{3+}} \), \( \mathrm{Zn^{2+}} \)
\( \mathrm{Ti^{4+}} \), \( \mathrm{Cu^{2+}} \)
\( \mathrm{V^{2+}} \), \( \mathrm{Ti^{3+}} \)
\( \mathrm{Zn^{2+}} \), \( \mathrm{Mn^{2+}} \)