Which of the following substituents on a benzene ring are meta directing?

Groups that withdraw electrons by resonance or by a strong inductive effect destabilise the ortho and para arenium ions more, so they direct meta. This applies to $-\mathrm{NO}{}_2$, $-\mathrm{CF}{}_3$ and $-\mathrm{COOH}$. $-\mathrm{OCH}{}_3$ donates by resonance and is ortho/para directing.