B
Members of large-animal species must consume enormous amounts of food to survive. When climatic conditions in their environment deteriorate, such animals are often unable to find enough food. This fact helps make large-animal species more vulnerable to extinction than small-animal species, which can maintain greater populations on smaller amounts of food. The statements above, if true, most support which one of the following?
A: When conditions deteriorate in a given environment, no small-animal species will become extinct unless some large-animal species also becomes extinct.
B: The vulnerability of an animal species to extinction depends at least in part on how much food individuals of that species must consume to survive.
C: Whenever climatic conditions in a given environment are bad enough to threaten large-animal species with extinction, small-animal species are able to find enough food to survive.
D: The maximum population size that an animal species could maintain on any given amount of food is the main factor determining whether that species will become extinct.