Which of the following compounds is formed by the addition of a mineral acid to an aqueous solution of borax?

Observe the following reactions (not balanced):
$BF_3 + LiAlH_4 \xrightarrow{(C_2H_5)_2O} X + LiF + AlF_3$
$X + NaH \longrightarrow Y$
The incorrect statement about $Y$ is:

Borax is actually made of two tetrahedra and two triangular units joined together and should be written as: $Na_2[B_4O_5(OH)_4] \cdot 8H_2O$. Consider the following statements about borax:
$a.$ Each boron atom has four $B-O$ bonds
$b.$ Each boron atom has three $B-O$ bonds
$c.$ Two boron atoms have four $B-O$ bonds while other two have three $B-O$ bonds
$d.$ Each boron atom has one $-OH$ group
Select correct statement$(s)$:

Consider the following statements for diborane $(B_2H_6)$:
$1.$ Boron is approximately $sp^3$ hybridized.
$2.$ $B-H-B$ angle is $180^{\circ}$.
$3.$ There are two terminal $B-H$ bonds for each boron atom.
$4.$ There are only $12$ bonding electrons available.
Which of these statements are correct?

Which elements of group $13$ possess both $+1$ and $+3$ oxidation state?

Identify the reaction in which diborane is produced on an industrial scale.