Compare ONO bond angle in nitrogen oxides

Question

Which has maximum $\ce{ONO}$ angle?

1. $\ce{NO3-}$
2. $\ce{NO2+}$
3. $\ce{NO2-}$
4. $\ce{NO2}$

According to me $\ce{NO2+}$ should have the maximum angle because the structure is linear but in answer it is given $\ce{NO3-}$. We can consider the lone pair in $\ce{NO2+}$ but still also by VSEPR theory I don't think it is possible to decrease angle from 180 to less than 120.

Answer 1

You are right, that's $\mathrm{NO_2^+}$, since it is linear, and whoever says otherwise is wrong.

Also, those (except for NO₂) are not compounds, but particles.