The compound(s) which react(s) with NH 3 to give boron nitride BN is(are)

The compound(s) which react with ${\mathrm{NH}}_3$ to form Boron nitride $\left(\mathrm{BN}\right)$ is/are:

(A) Amorphous $\mathrm{B}+{\mathrm{NH}}_3\underset{ \mathrm{Tempreature} }{⟶}\mathrm{BN}+{\mathrm{H}}_2$

(B) ${\mathrm{B}}_2{\mathrm{H}}_6+\underset{\left(\mathrm{excess}\right)}{{\mathrm{NH}}_3}\stackrel{ \mathrm{HighTemp}. }{⟶}{\left(\mathrm{BN}\right)}_{\mathrm{x}}$

(C) ${\mathrm{B}}_2{\mathrm{O}}_3+2{\mathrm{NH}}_3\stackrel{900°\mathrm{C}}{⟶}2\mathrm{BN}+3{\mathrm{H}}_2\mathrm{O}$

(D) ${\mathrm{HBF}}_4+{\mathrm{NH}}_3⟶\left[{\mathrm{NH}}_4^{\oplus }\right]\left[{\mathrm{BF}}_4^{\ominus }\right]$

Hence, (A,B,C) are correct