Whether a Sugar Starts Out as a Fructose, Galactose, or Glucose

Multiple Choice

Whether a sugar starts out as a fructose, galactose, or glucose, it must undergo enzyme-catalyzed reactions in order to become a single type of monosaccharide so that it can go through the second stage of catabolism, glycolysis. Which monosaccharide must all of these sugars become?

A) fructose
B) galactose
C) mannose
D) talose
E) glucose