During strenuous exercise, the NADH formed in the glyceraldehyde 3-phosphate dehydrogenase reaction in skeletal muscle must be reoxidized to NAD+ if glycolysis is to continue. The most important reaction involved in the reoxidation of NADH is:

A) dihydroxyacetone phosphate β†’ glycerol 3-phosphate
B) glucose 6-phosphate β†’ fructose 6-phosphate
C) isocitrate β†’ Ξ±-ketoglutarate
D) oxaloacetate β†’ malate
E) pyruvate β†’ lactate