The oxidation of toluene with air in the presence of $V_2O_5$ gives ...........

The product $A$ in the following reaction is:
$CH_3-CH=CH-CH_2-CN \xrightarrow[(2) H_3O^+]{(1) DIBAL-H, -78^{\circ}C} A$

$CH_3CH_2C \equiv N \xrightarrow{X} CH_3CH_2CHO$. The compound $X$ is:

Benzonitrile $(C_6H_5CN)$ reacts with a Grignard reagent in dry ether followed by hydrolysis to form benzophenone $(C_6H_5COC_6H_5)$ along with ammonia $(NH_3)$ and hydroxymagnesium bromide $(Mg(OH)Br)$. Identify the reagent used in the above transformation.

Benzonitrile on reduction with stannous chloride $(SnCl_2)$ in the presence of hydrochloric acid $(HCl)$ followed by acid hydrolysis forms:

Which,if any,of the following pairs of reagents could be used to prepare $2$-phenyl-$2$-butanol?