Since the −NH2 group is ortho/para directing, the arenium ion will not be formed by attack at the meta position. This is due to the electron-donating nature of the −NH2 group, which stabilizes the carbocation at the ortho and para positions relative to itself.
Thus, the arenium ion corresponding to the meta substitution, as shown in answer (3), does not participate in the bromination of aniline.
So, the correct answer is: Option (3)