Which one of the following is correct statement ?

Boron is the only non-metal in group-13 and its hydroxide is acidic. Boron hydroxide is formed when borax is treated with acid in the presence of water. On heating, boric hydroxide forms meta-boric acid.

$\mathrm{B}{\left(\mathrm{OH}\right)}_3\stackrel{∆}{\to }\underset{\mathrm{Metaboric} \mathrm{acid}}{{\mathrm{HBO}}_2}+{\mathrm{H}}_2\mathrm{O}$

Aluminum hydroxide is amphoteric because it reacts with both acid and base.

$\begin{array}{ccc}\mathrm{Al}{\left(\mathrm{OH}\right)}_3+3\mathrm{HCl}& \to & {\mathrm{AlCl}}_3+3{\mathrm{H}}_2\mathrm{O}\\ \mathrm{Al}{\left(\mathrm{OH}\right)}_3+\mathrm{NaOH}& \to & {\mathrm{NaAlO}}_2+2{\mathrm{H}}_2\mathrm{O}\end{array}$