Step 1: Hydrolysis of the nitrile.
Propanenitrile on basic hydrolysis followed by acidic workup gives propanoic acid:
CH3−CH2−C≡N(i) OH−/H2O/Δ(ii) H3O+CH3−CH2−COOH
Step 2: Hell−Volhard−Zelinsky (HVZ) reaction.
Propanoic acid has an sp3 α-carbon bearing two α-hydrogens. In the HVZ reaction, Cl2 in the presence of red phosphorus selectively replaces one α-hydrogen by chlorine, giving the α-chloro acid after aqueous workup:
CH3−CH2−COOH(iii) Cl2/Red P(iv) H2OCH3−CH(Cl)−COOH
Hence, the major product P is 2-chloropropanoic acid, which corresponds to option (1).