Question ID:PT48 S1 Q25 Passage:Almost all microbe species live together in dense, interdependent communities, supporting the environment for each other, and regulating the population balances for their different species through a complex system of chemical signals. For this reason, it is currently impossible to cultivate any one such species in isolation. Thus, microbiologists lack complete knowledge of most microbe species. Stem:Which one of the following, if assumed, enables the argument's conclusion to be properly drawn? Correct Answer Choice:CChoice A:It is currently impossible for microbiologists to reproduce the complex systems of chemical signals with which microbe communities regulate the population balances for their different species. Choice B:If it is currently impossible to reproduce the environmental supports and chemical signals in dense, interdependent communities of microbe species, then it is also impossible to cultivate any microbe species from such a community in isolation. Choice C:No microbiologist can have complete knowledge of any species of organism unless that microbiologist can cultivate that species in isolation. Choice D:At least some microbiologists lack complete knowledge of any microbe species that live together in dense, interdependent communities. Choice E:No microbe species that normally lives together with other microbe species in dense, interdependent communities can survive outside such a community.