The major product in the above reaction is :

Solution

Chemistry ma’am · 3 steps

Two NH2 groups, but only one is a real nucleophile: the benzylic amine gets acetylated, not the amide.

1. What acetylation needs. Acetic anhydride, (CH₃CO)₂O, is attacked by a nitrogen lone pair, which then takes the acetyl group. The more available the lone pair, the faster that nitrogen reacts.

   Nitrogen	Where its lone pair is	Reacts with (CH₃CO)₂O?
   -CH₂NH₂ (benzylic amine)	Localised on N. The CH₂ keeps it away from the ring.	Yes, it is a strong nucleophile
   -CONH₂ (amide)	Delocalised into the C=O by resonance	No, it is a very weak nucleophile

2. Product. The -CH₂NH₂ group becomes -CH₂NHCOCH₃. The -CONH₂ group stays unchanged.
3. So. The major product is the one with the acetamidomethyl group and an intact amide, which is option (d).

The idea to keep. Before acylating, ask where each nitrogen's lone pair lives. A lone pair delocalised into a C=O (amide) is not available, so only the free amine gets acetylated.

Answer from the NTA final answer key. Solution by PrepWiser.