How many of the following molecules are meso compounds?

(C) meso compound is a molecule with multiple stereocenters that is achiral due to an internal plane of symmetry or center of inversion.
$1$. The first molecule is $2,5$-dibromo-$1,4$-dioxane. The structure shown has one $Br$ atom on a wedge and one on a dash. This configuration possesses a center of inversion,making it a meso compound.
$2$. The second molecule is a sugar derivative. It has a plane of symmetry passing through the $C=O$ group,effectively bisecting the molecule into two identical halves. Thus,it is a meso compound.
$3$. The third molecule is $1$-chloro-$1$-methylcyclohexane. This molecule has a plane of symmetry passing through the $C1$ atom and the $C4$ atom of the cyclohexane ring. However,it does not have any stereocenters (the $C1$ carbon is attached to two identical ring paths),so it is achiral but not a meso compound.
Therefore,there are $2$ meso compounds.