Compared to the Numbers of Grasshoppers or Deer,there Are Few

Multiple Choice

Compared to the numbers of grasshoppers or deer,there are few mountain lions.The reason that large and fierce animals,such as the mountain lion,are rare in an ecosystem is that

A) such animals do not tolerate other members like them.
B) through evolution,most fierce animals have been killed off by others.
C) food chains are only 10-20% efficient at each step and top carnivores require large amounts of calories for their survival.
D) only a few such animals are permitted by succession in a biome and there are only a few biomes.
E) more large predators bring more disease to an ecosystem.