Compound (A) on reduction with `LiAIH_4` gives a hydribe (P) containing 21.72% hydrogen along with other products.The one mole of hydride (P) and 2 moles of ammonia at higher temperature gives a compound (Q) which is known as inorganic benzene. (A) hydrolyses incompletely and forms a compound (R) and `H_3BO_2`
The hybridisation of central atom of compound (R) is :
A. `sp^2`
B. `sp^3`
C. `sp`
D. `sp^3d`