The right answer is smelly garbage.
Infestation is the penetration into the body of a parasite whose nature is not microbial.
smelly garbage is not synonymous of infestation, because the olfactory system only detected smelly metabolites of these microorganisms. This does not necessarily mean that the microorganism has managed to penetrate the body.
By cons other proposals are signs and tools for infestation (torn packaging with food leaking out, dead insect bodysuits, feathers, and fur).
A unicellular organism must perform all functions necessary for life. A multicellular organism has specialized cells, tissues, organs, and organ systems that perform specific functions.
Answer:
I think the awnser is D. Hope it helps
There are so many examples for that in different areas, like TPT1 experiment carried out in our lab recently.Here's one link: http://www.alfa-chemistry.com/tpt1-cas-167218-46-4-item-290583.htm