Concept: Negative resonance effect ($-R$ or $-M$ effect)

A functional group shows negative resonance effect when it withdraws electrons through resonance from the attached conjugated system.

Typical groups showing $-R$ effect are: $-CHO,\;-COR,\;-COOH,\;-COOR,\;-CN,\;-NO_2$

Check each option

A: $-OH$

• Oxygen has lone pairs.
• It can donate electron density by resonance into a conjugated system.
• Hence, $-OH$ shows positive resonance effect $(+R)$.

B: $-OR$

• Like $-OH$, the oxygen atom has lone pairs.
• It donates electrons by resonance.
• So, $-OR$ also shows positive resonance effect $(+R)$.

C: $-COOH$

• The carboxyl group contains a carbonyl system.
• It withdraws electron density by resonance from the attached chain/ring.
• Therefore, $-COOH$ shows negative resonance effect $(-R)$.

D: $-NH_2$

• Nitrogen has a lone pair.
• It donates electron density by resonance.
• So, $-NH_2$ shows positive resonance effect $(+R)$.

Conclusion

The only group among the given options showing negative resonance effect is: $\boxed{-COOH}$

Comparison with stored answer

Stored correct answer: C

Derived answer: C

These match.