15. Which of the following best states the central idea of the passage?
(A) The disadvantage of a low oxidative metabolic rate in large animals can be offset by their ability to convert substantial amounts of glycogen into energy.
(B) The most significant problem facing animals that have used anaerobic glycolysis for energy is the resynthesis of its by-product, glucose, into glycogen.
(C) The benefits to animals of anaerobic glycolysis are offset by the profound costs that must be paid.
(D) The major factor ensuring that a large animal will triumph over a smaller animal is the large animal’s ability to produce energy via anaerobic glycolysis.
(E) The great differences that exist in metabolic rates between species of small animals and species of large animals can have important effects on the patterns of their activities.