Which of the structures shown are meso compounds (achiral in spite of having stereocentres)?

(A) is (2R,4S)-2,4-dibromopentane: C2 and C4 have opposite configurations and a mirror plane passes through C3, so it is meso. (B) is cis-1,2-dibromocyclohexane, (1R,2S): a mirror plane bisects the C1-C2 bond, so it is meso. (C) is (2R,3R)-2,3-dichlorobutane, which is chiral. (D) is 2,3-dibromopentane, whose two stereocentres carry different groups ($\mathrm{CH}{}_3$ versus $\mathrm{C}{}_2\mathrm{H}{}_5$), so no meso form is possible and it is chiral.