Principle of extraction with $1\text{ M HCl}$

Dilute hydrochloric acid extracts basic compounds into the aqueous layer by converting them into their water-soluble hydrochloride salts.

So, among the given compounds, we must identify the one that behaves as a base and gets protonated by $\text{HCl}$.

Which type of compound goes into aqueous layer?

• Amines are basic due to the lone pair on nitrogen.
• On treatment with $\text{HCl}$: $RNH_2 + HCl \rightarrow RNH_3^+Cl^-$
• The resulting ammonium salt is ionic and dissolves in water, so it moves to the aqueous layer.

Examine the four compounds

From the given set, compound (II) is the one containing the basic amine functionality capable of forming a salt with $\text{HCl}$.

The other compounds do not form stable water-soluble salts under these conditions and therefore remain in the organic layer.

Conclusion

Therefore, the compound that goes to the aqueous layer on extraction with $1\text{ M HCl}$ is: $\boxed{\text{(II)}}$

Comparison with stored answer

Stored correct answer = B

Our derived answer = B

Hence, they agree.