The set in which compounds have different nature is:
\( \mathrm{B(OH)_3} \) and \( \mathrm{Al(OH)_3} \)
\( \mathrm{NaOH} \) and \( \mathrm{Ca(OH)_2} \)
\( \mathrm{Be(OH)_2} \) and \( \mathrm{Al(OH)_3} \)
\( \mathrm{B(OH)_3} \) and \( \mathrm{H_3PO_3} \)