The compound shown is treated with $\mathrm{Br}{}_2$ and $\mathrm{FeBr}{}_3$. Which structure is the major product of ring bromination?

The compound is acetophenone. The acetyl group is deactivating and meta-directing, because the carbonyl withdraws electrons by resonance and induction and destabilises ortho and para attack. Under Lewis-acid conditions the ring is brominated, giving 3-bromoacetophenone (the alpha-bromoketone would need acid or radical conditions, not $\mathrm{FeBr}{}_3$).