Which one of the following on reduction with lithium aluminium...

$\mathrm{R}-\mathrm{N} \equiv \mathrm{C}+4[\mathrm{H}] \stackrel{\mathrm{LAIH}_4}{\longrightarrow} \underset{2^{\circ} \text{ amine }}{\mathrm{R}-\mathrm{NH}-\mathrm{CH}_3}$ On reaction with $\mathrm{LiAlH}_4$, Isocyanate groups gives secondary amines whereas, alkyl cyanides give $1^{\circ}$ amine on reduction. Related Theory LiAlH $_4$ is a nucleophilic reducing agent since the hydride transfer to the carbonyl carbon occurs prior to the coordination to the carbonyl oxygen. It reacts faster with electron deficient carbonyl groups. The reactivity of carbonyl compounds with this reagent follows the order: Aldehydes $>$ Ketones $>$ ester $>$ amide $>$ carboxylic acid.