Which of the following findings about widely scattered tracts 10 kilometers by 10 kilometers in a temperate climate zone would most seriously challenge the conservationists' assumptions? A. The tracts show little damage from human intrusion and from pollution by human activities. B. Where a certain group of species, such as birds, is abundant, there is also an abundance of the species, such as insects, on which that group of species feeds, or in the case of plants, of the land and water resources it requires. C. The area of one of the tracts is generally large enough to contain a representative sample of the organisms in the region. D. There is little overlap between the list of tracts that are rich in species of butterflies and the list of those that are rich in species of birds. E. The highest concentration of individuals of rare species is found where the general diversity of species is greatest.