Complete the following reaction sequence and give the name of major...

Step 1: Hydrolysis of the nitrile.
Propanenitrile on basic hydrolysis followed by acidic workup gives propanoic acid:
$CH_3-CH_2-C \equiv N \xrightarrow[(ii)\ H_3O^+]{(i)\ OH^-/H_2O/\Delta} CH_3-CH_2-COOH$

Step 2: Hell$-$Volhard$-$Zelinsky (HVZ) reaction.
Propanoic acid has an $sp^3$ $\alpha$-carbon bearing two $\alpha$-hydrogens. In the HVZ reaction, $Cl_2$ in the presence of red phosphorus selectively replaces one $\alpha$-hydrogen by chlorine, giving the $\alpha$-chloro acid after aqueous workup:
$CH_3-CH_2-COOH \xrightarrow[(iv)\ H_2O]{(iii)\ Cl_2/\text{Red P}} CH_3-CH(Cl)-COOH$

Hence, the major product $P$ is $2$-chloropropanoic acid, which corresponds to option $(1)$.