This answer is correct! The reaction gains negative character at the reaction site and this will be favored by electron withdrawing inductive effects. There is no resonance of the negative charge on oxygen into the aromatic ring from the carboxylate anion.

The nitro group has an electron withdrawing full charge dipole.

When the nitro group has resonance into the aromatic ring, this resonance dipole will also be electron withdrawing. Both of these dipoles combine to form an overall strong electron withdrawing substituent on the carboxylate anion.