When a Mixture of Glucose 6-Phosphate and Fructose 6-Phosphate Is $\leftrightarrow$

When a mixture of glucose 6-phosphate and fructose 6-phosphate is incubated with the enzyme phosphohexose isomerase, the final mixture contains twice as much glucose 6-phosphate as fructose 6-phosphate. Which statement is MOST nearly correct, when applied to the reaction below (R = 8.315 J/mol · K and T = 298 K) ? glucose 6-phosphate $\leftrightarrow$ fructose 6-phosphate

A) $\Delta$ G'° is +1.7 kJ/mol.
B) $\Delta$ G'° is -1.7 kJ/mol.
C) $\Delta$ G'° is incalculably large and negative.
D) $\Delta$ G'° is incalculably large and positive.
E) $\Delta$ G'° is zero.