Because adult iguanas on Plazos Island are

题目：

Because adult iguanas on Plazos Island are much smaller than adult iguanas of the same species on nearby islands, researchers assumed that environmental conditions on Plazos favor the survival of relatively smaller baby iguanas (hatchlings) in each yearly brood. They discovered instead that for each of the past three years, 10 percent of the smaller and 40 percent of the larger hatchlings survived, because larger hatchlings successfully evade their predators.
Which of the following, if true about Plazos but not about nearby islands, contributes most to an explanation of the long-standing tendency of iguanas on Plazos to be smaller than those of the same age on nearby islands

A．Periodic wind shifts cause extended dry spells on Ptazos every year, putting the larger iguanas, whose bodies require relatively more water, at a great disadvantage.

B．There are exactly three species of iguanas on Plazos but only two species of seagulls that feed on iguanas, and a relatively small percentage of each year’s hatchlings are consumed by seagulls.

C．Wild cats, which were introduced as pets by early settlers and which were formerly major predators of Plazos iguanas, were recently killed off by a disease specific to cats.

D．The iguanas on Plazos are a relatively ancient part of the island’s animal life.

E．(E) Both land and marine iguanas live on Plazos, and the land iguanas tend to be larger than marine iguanas of the same age.