In the leaching of alumina from bauxite, the ore expected to leach out in the process by reacting with \( \mathrm{NaOH} \) is:
\( \mathrm{TiO_2} \)
\( \mathrm{Fe_2O_3} \)
\( \mathrm{ZnO} \)
\( \mathrm{SiO_2} \)