52. Birds need so much food energy to maintain their body temperatures that some of them spend most of their time eating. But a comparison of a bird of a seed-eating species to a bird of a nectar-eating species that has the same overall energy requirement would surely show that the seed-eating bird spends more time eating than does the nectar-eating bird, since a given amount of nectar provides more energy than does the same amount of seeds
The argument relies on which one of the following questionable assumptions
A. Birds of different species do not generally have the same overall energy requirements as each other
B. The nectar-eating bird does not sometimes also eat seeds
C. The time it takes for the nectar-eating bird to eat a given amount of nectar is not longer than the time it takes the seed-eating bird to eat the same amount of seeds
D. The seed-eating bird does not have a lower body temperature than that of the nectar-eating bird
E. The overall energy requirements of a given bird do not depend on factors such as the size of the bird, its nest-building habits; and the climate of the region in which it lives
我觉得题目问的是这个argument依赖下面哪个假设，如果依赖c的话，n鸟吃一定数量的nectar的时间不长于s鸟吃一定数量的seed，也就是n鸟吃的要比s鸟快，至少一样，但如果这样的话，问题里说的n鸟用在吃nectar的时间要比s鸟少的原因是因为n鸟吃得快从而有可能吃的数量比s鸟多，而不可能是因为单个nectar的能量大了，而这样就削弱它的论述了，所以文章不能依赖这个假设啊？谢谢nn解答 | 
