1. Use Hinsberg test idea

An amine reacts with benzenesulphonyl chloride, $C_6H_5SO_2Cl$.

• Primary amine ($1^\circ$) gives sulphonamide having an acidic $N-H$, so it is soluble in alkaline solution.
• Secondary amine ($2^\circ$) gives sulphonamide with no acidic hydrogen on nitrogen, so it is insoluble in alkaline solution.
• Tertiary amine ($3^\circ$) generally does not form sulphonamide in this test.

Since the product is insoluble in alkaline solution, the given amine must be a secondary amine.

2. Now check which amine can be prepared by ammonolysis of ethyl chloride

Ammonolysis of ethyl chloride, $C_2H_5Cl$, gives ethyl-substituted amines such as:

Further alkylation can give:

So a secondary amine obtainable from ethyl chloride is diethylamine, $(C_2H_5)_2NH$.

3. Evaluate options

• A: $CH_3CH_2NH_2$ = ethylamine, a primary amine. Wrong.
• B: $CH_3CH_2CH_2NHCH_3$ = methyl propyl amine, secondary amine, but it cannot arise from ammonolysis of only ethyl chloride because it contains methyl and propyl groups. Wrong.
• C: $CH_3CH_2CH_2\,\overset{H}{N}\!- CH_2CH_3$ as printed corresponds to an amine containing propyl and ethyl groups, not obtainable from only ethyl chloride. So as written, this is also inconsistent.

However, from the condition of the question, the required amine must be diethylamine, i.e.

This suggests option C is likely intended to represent diethylamine (common printing/formatting issue in the statement/options).

4. Final conclusion

The amine must be a secondary amine produced from ammonolysis of ethyl chloride, hence it is:

So the intended correct option is C.