Which of the Following Concerning the Isomerase Reaction of Glucose-6-Phosphate

Which of the following concerning the isomerase reaction of glucose-6-phosphate to fructose-6-phosphate is correct?

A) Zn²⁺ is required for activity.
B) It is a ketose-to-aldose isomerization.
C) Transferring the carbonyl from C-1 to C-2 creates a new primary alcohol group at C-1.
D) The reaction is irreversible with a large negative ∆G.