13. The passage suggests that the total anaerobic energy reserves of a vertebrateare proportional to the vertebrate’s size because
(A) larger vertebrates conserve more energy than smaller vertebrates
(B) larger vertebrates use less oxygen per unit weight than smaller vertebrates
(C) the ability of a vertebrate to consume food is a function of its size
(D) the amount of muscle tissue in a vertebrate is directly related to its size
(E) the size of a vertebrate is proportional to the quantity of energy it can utilize