The false statement among the followings:

Options

1. AThe average residence time of $\mathrm{NO}$ is one month.
2. BLimestone acts as a sink for $\mathrm{SO}_{\mathrm{x}}$
3. C$\mathrm{SO}_{\mathrm{x}}$ can be removed from flue gases by passing through a solution of citrate ions.
4. DAmmonia acts as a sink for $\mathrm{NO}_{\mathrmx^{-}}$