During mitosis the four centrioles appear visibly and move to the ends of the nucleus one pair at each end<span> then they produce a series of threads that attach to the chromosomes During cell division the threads split the chromosomes and drew them towards the centrioles</span>
Space satellites
Environmental
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).