Which of the following ions will exhibit colour in aqueous solutions?

Color in transition metal ions is usually due to $d-d$ transitions, which require the presence of unpaired electrons in the $d$ -subshell.${\text{Sc}}^{3+}:[Ar]3d^0$ (No $d$ electrons).${\text{La}}^{3+}:[Xe]4f^{0}5d^0$ (No $d$ or $f$ electrons).${\text{Ti}}^{3+}:[Ar]3d^1$ (One unpaired electron). Will be coloured.${\text{Lu}}^{3+}:[Xe]4f^{14}5d^0$ (No unpaired $d$ electrons).