Trihydroxyglutaric acid is $\mathrm{HOOC}-\mathrm{CH}(\mathrm{OH})-\mathrm{CH}(\mathrm{OH})-\mathrm{CH}(\mathrm{OH})-\mathrm{COOH}$ (2,3,4-trihydroxypentanedioic acid). Counting configurational stereoisomers, select the correct statements.

Fischer-projection enumeration of the three OH groups (left/right) gives 8 arrangements; rotating by 180 degrees in the plane pairs them into 4 stereoisomers. Two of these have C2 and C4 with mirror-related configurations (2R,4S), giving two meso forms in which C3 is pseudoasymmetric. The other two have C2 and C4 of the same descriptor (2R,4R / 2S,4S) and form one enantiomeric pair; in them C3 carries two identical groups and is not stereogenic. So D is false.