Canine phosphofructokinase PFK) deficiency afflicts springer spaniels, affecting an estimated 10% of the breed. PFK is the glycolytic enzyme that phosphorylates fructose- 1- phosphate and catalyzes the committed step in glycolysis. Given its critical role in glycolysis, one implication of the genetic defect resulting in PFK deficiency in dogs is
A) elevated blood- glucose levels. B) nothing. It would have no visible effect on the health of the animal. C) exercise intolerance. D) early embryonic mortality.