Boric acid is an acid because its molecule

Which one of the following is correct relating to diborane $(B_2H_6)$?

Which hydrated elements of group $13$ are found as polymers in nature?

In which of the following does the inert pair effect play a significant role?

For the following halides: $(1) \ BCl_3$,$(2) \ AlCl_3$,$(3) \ GaCl_3$,$(4) \ InCl_3$,what is the decreasing order of their Lewis acid strength?

Which of the following reactions can be used to prepare diborane?
$I. BF_3 + LiAlH_4 \xrightarrow{\text{ether}}$
$II. BF_3 + NaH \xrightarrow{450 \ K}$
$III. Na_2B_4O_7 + H_2O \longrightarrow$
$IV. NaBH_4 + I_2 \longrightarrow$