Which of the following statements is incorrect for $B_2H_6$?

$AlCl_3$ on hydrolysis gives:

The structure of $Na_2[B_4O_5(OH)_4] \cdot 8H_2O$ contains:

The correct statements among $I$ to $III$ regarding group $13$ element oxides are,
$I$. Boron trioxide is acidic
$II$. Oxides of aluminium and gallium are amphoteric
$III$. Oxides of indium and thallium are basic

The correct statement$(s)$ for orthoboric acid $(H_3BO_3)$ is/are:
$(A)$ It behaves as a weak acid in water due to self-ionization.
$(B)$ Acidity of its aqueous solution increases upon addition of ethylene glycol.
$(C)$ It has a three-dimensional structure due to hydrogen bonding.
$(D)$ It is a weak electrolyte in water.

The reaction of $H_{3}N_{3}B_{3}Cl_{3}$ $(A)$ with $LiBH_{4}$ in tetrahydrofuran gives inorganic benzene $(B)$. Further,the reaction of $(A)$ with $(C)$ leads to $H_{3}N_{3}B_{3}(Me)_{3}$. Then,compounds $(B)$ and $(C)$ respectively,are