Which is NOT a valid reason why species diversity is economical to humans? A) A diverse set of microbes in waterways can eliminate more pollutants, saving humans the cost of clean up. B) More diverse species of trees in a forest compete less for resources yielding more money for logging industry. C) A diverse population of bacteria attacking the body is much more economical than just one population of bacteria. D) Keeping a diverse set of pollinators on farms allows crops to be pollinated at different times yielding higher crops.