The author's explanation of why human beings have evolved as superior distance runners would be most weakened if it were shown that A. early humans typically hunted animals that were less well adapted than humans for long-distance running B. early humans were only one of a number of species that hunted prey on the African savannas C. early humans hunted mainly in groups by sneaking up on prey and trapping it within a circle D. hunting was just as essential for later humans in colder climates as it was for early humans on the African savannas E. human beings of today have retained the ability to run long distances but no longer hunt by chasing prey