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 one of the following statements is MOST 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) is +1.7 kJ/mol.
B) is -1.7 kJ/mol.
C) is zero.
D) It is not possible to calculate