Answer:
c. O−N=OO−N=O and O=N−OO=N−O
Explanation:
The resonance consists of the linear combination of structures of a molecule, that is to say resonant structures, that do not coincide with the real structure, but that by means of their combination brings us closer to its real structure.
Each resonance structure must have the same number of electrons, atoms, and the same net charge.
In resonance structures, atoms must not change position, only electrons change position.