Identify the correct statement for $B _{2} H _{6}$ from those given below.

$(A)$ In $B _{2} H _{6}$, all $B – H$ bonds are equivalent.

$(B)$ In $B _{2} H _{6}$ there are four $3-$centre$-2-$electron bonds.

$(C)$ $B _{2} H _{6}$ is a Lewis acid.

$(D)$ $B _{2} H _{6}$ can be synthesized form both $BF _{3}$ and $NaBH _{4}$.

$(E)$ $B _{2} H _{6}$ is a planar molecule.

Choose the most appropriate answer from the options given below….. .

A compound $(A)$ of boron reacts with $NMe_3$ to give an adduct $(B)$ which on hydrolysis gives a compound $(C) $ and hydrogen gas. Compound $(C)$ is an acid. Identify the compounds $A, B$ and $C.$ Give the reactions involved. 

In which of the following reaction, the hybridisation of the central atom changes from $sp^2$ to $sp^3$ ?

In which of the following, a salt of the type $KMO_2$ is obtained?

Draw structure of diboren.