Standard electrode potential values for ${\mathrm{Al}}^{3+}/\mathrm{Al}$ is $–1.66\mathrm{V}$ and that of ${\mathrm{Tl}}^{3+}/\mathrm{Tl}$ is $+1.26 \mathrm{V}$. then,

• Al would easily ionise in solution, whereas Ti would not.
• Moreover, compared to titanium(Ti), aluminium (Al) is more electropositive.

Therefore, the correct option is (A).