Which Carbon Atom in One of the Glycolytic Intermediates Shown

Multiple Choice

Which carbon atom in one of the glycolytic intermediates shown below would have to be radiolabeled with ¹⁴C in order to ensure all the radioactivity would be release as ¹⁴CO₂ during alcoholic fermentation?

A) C6 of glucose 6-phosphate.
B) C3 of fructose 1,6-bisphosphate.
C) C1 of pyruvate.
D) C2 of glyceraldehyde 3-phosphate.
E) C5 of fructose 6-phosphate.