(d)
The order of reactivity of acid derivatives is as
$RCOCl > (RCO)_{2}O > RCOOR^{'} > RCONH_{2}$
Hence, acetyl chloride is the most reactive among these.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.