Why does the author state that Leeuwenhoek "failed to see the single-celled 'animalcules' reproduce?" A. to argue that Leeuwenhoek intentionally ignored some of what he saw with his microscope B. to suggest that Leeuwenhoek was not as important a researcher as he has traditionally been considered C. to explain why Leeuwenhoek did not challenge the idea that life could emerge from nonliving material D. to contrast Leeuwenhoek's observations with those of earlier researchers