The acid formed when propyl magnesium bromide is treated with carbon dioxide is:

In the reaction:

${\mathrm{CH}}_3\mathrm{CN}+2\mathrm{H}\underset{\mathrm{Ether}}{\overset{\mathrm{HCl}}{\to }}\mathrm{X}\underset{{\mathrm{H}}_2\mathrm{O}}{\overset{\mathrm{Boiling}}{\to }}\mathrm{Y};$ the term $\mathrm{Y}$ is:

In a set of reactions, propionic acid yielded a compound $\mathrm{D}$.

${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COOH}\stackrel{{\mathrm{SOCl}}_2}{⟶}\mathrm{B}\stackrel{{\mathrm{NH}}_3}{\to }\mathrm{C}\underset{{\mathrm{Br}}_2}{\overset{\mathrm{KOH}}{\to }}\mathrm{D}$

The structure of $\mathrm{D}$ would be