The following genes ____________________ for carbohydrate metabolism are housekeeping genes in humans. A: lactate dehydrogenase (LDHA),GDP-L-fucose synthetase (TSTA3), & fructose-bisphosphate aldolase (aldolase A, ALDA) B: enolase phosphatase (ENOPH1) & triose-phosphate isomerase (TPI) C: phosphoglycerate kinase (PGK1) & glycogen synthase kinase-3 (GSK3A/B) D: transaldolase in pentose shunt (TALDO1) & phosphoglycerate mutase (PGM)

Which one of the following enzymatic reactions is reversible? ( ) A: The reaction catalyzed by glycogen phosphorylase B: The reaction catalyzed by phosphoglycerate kinase C: The reaction catalyzed by pyruvate kinase D: The reaction catalyzed by fructose bisphosphatase-1 E: The reaction catalyzed by hexokinase