The most stable resonating structure of the intermediate arenium lon is

• The amino group (–NH₂) is an electron-donating group due to its lone pair of electrons on nitrogen.

Through resonance, the lone pair on nitrogen delocalizes into the benzene ring, increasing electron density at the ortho and para positions.

During electrophilic substitution (E⁺ attack), the arenium ion (σ-complex) forms.

The most stable resonance structure of the arenium ion is the one in which the positive charge is delocalized onto the nitrogen atom.

This happens because nitrogen can stabilize the positive charge through its lone pair, leading to maximum stability.

Final Answer:
The most stable resonating structure of the arenium ion is the one where the positive charge is on the nitrogen atom of the –NH₂ group due to resonance donation, i.e., the electrophile attaches at the para (or ortho) position and the charge delocalizes onto nitrogen.