The main reduction product of the following compound with ${\mathrm{NaBH}}_4$ in methanol is :

The major product of following reaction is : 

$\mathrm{R}-\mathrm{C}\equiv \mathrm{N}\underset{\left(2\right){\mathrm{H}}_2\mathrm{O}}{\overset{\left(1\right) \mathrm{AlH}(\mathrm{i}-\mathrm{Bu}{)}_2}{\to }}?$

The major product $\text{'}\mathrm{X}\text{'}$ formed in the following reaction is:

The major product of the following reaction. is:

The major product of the following reaction. is:

The major product obtained in the following reaction is :

The major product of the following reaction is :

The major product of the following reaction is :