The Enzyme Phosphofructokinase Is the Major Regulatory Enzyme of Glycolysis

The enzyme phosphofructokinase is the major regulatory enzyme of glycolysis.It catalyzes _____.

A) the phosphorylation of ADP to ATP
B) the isomerization of glucose 6-phosphate to fructose 6-phosphate
C) the phosphorylation of fructose 6-phosphate
D) the substrate-level phosphorylation reaction whereby phosphoenolpyruvate is converted to pyruvate