Test Preparation on Aldehyde & Ketone-II-Chemistry Test Series IIT JEE-2020

Paraldehyde is used as a

3CH3COCH3 ¾H¾¾Cl®(CH3 )2C = CH -CO -CH = C(CH3 )2
This polymer (2) is obtained when acetone is saturated with
hydrogen chloride gas, B can be

Which one of the following on oxidation will not give a carboxylic acid with the same number of carbon atoms