The functional group that shows negative resonance effect is:

Step-by-step solution

The resonance effect definition can be given as a chemical phenomenon, observed in the characteristic compounds containing double bonds in the organic compounds. The organic compounds have these double bonds in the structures and have the overlapping of the p-orbitals, usually on the two adjacent sides of carbon atoms. Negative Resonance Effect: The Negative resonance effect happens when the groups withdraw the electrons from the other molecules by the delocalisation process. Usually, the groups are denoted either