A compound X, of boron, reacts with NH3 on heating to give another compound Y which is called inorganic benzene. The compound X can be prepared by treating BF3 with lithium aluminum hydride. The compounds X and Y are represented by the formulas.

1.  B2H6, B3N3H6

2.  B2O3, B3N3H6

3.  BF3, B3N3H6

4.  B3N3H6, B2H6