What Is the Intracellular Glucose Concentration If The $\Delta$ G for the Following Reaction Is -20

What is the intracellular glucose concentration if the $\Delta$ G for the following reaction is -20.1 kJ/mol at 37°C and concentrations for glucose-6-phosphate and phosphate are both 1 mM?
Glucose-6-phosphate glucose + P_i $\Delta$ G° = -13.8 kJ/mol

A) 1.9 $\mu$ M
B) 87 $\mu$ M
C) 1.9 mM
D) 27 mM
E) 87 mM