The reaction $\mathrm{R}-\mathrm{CO}-\mathrm{R}\stackrel{{\mathrm{N}}_3\mathrm{H}/{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }\mathrm{RCONHR}+{\mathrm{N}}_2$ is called

 The reaction $\mathrm{R}-\mathrm{CO}-\mathrm{R}\stackrel{{\mathrm{N}}_3\mathrm{H}/{\mathrm{H}}_2{\mathrm{SO}}_4}{\to }\mathrm{RCONHR}+{\mathrm{N}}_2$ is calledSchmidt reaction.

 In organic chemistry, the Schmidt reaction is an organic reaction in which an azide reacts with a carbonyl derivative, usually an aldehyde, ketone, or carboxylic acid, under acidic conditions to give an amine or amide, with the expulsion of nitrogen.

Hence, the correct answer is option C) Schmidt reaction.