Aniline is diazotised ( $NaNO X_{2}$ , $HCl$ , 273 K), the product is heated with $CuBr$ and $HBr$ , the resulting compound is converted to its Grignard reagent with $Mg$ in dry ether, and finally $D X_{2} O$ is added. The final organic product is

Answer: D

Diazotisation and the Sandmeyer reaction give bromobenzene.

Mg

in dry ether gives

C X_{6} H X_{5} MgBr

. The strongly basic carbon of the Grignard reagent is protonated (here deuterated) by

D X_{2} O

C X_{6} H X_{5} MgBr + D X_{2} O C X_{6} H X_{5} D + Mg (OD) Br