18. There is reciprocal regulation of glycolytic and gluconeogenic reactions interconverting fructose-6-phosphate and fructose-1,6-bisphosphate. Which one of the following statements about this regulation is not correct? (A) Fructose-2,6-bisphosphate activates phosphofructokinase-1. (B) Fructose-2,6-bisphosphate inhibits fructose-1,6-bisphosphatase. (C) The fructose-1,6-bisphosphatase reaction is exergonic. (D) The phosphofructokinase-1 reaction is endergonic. (E) This regulation allows control of the direction of net metabolite flow through the pathway.