Solution: (d) One creature benefits, while the other is affected.
Parasitism is a sort of interspecies interaction in which one species (parasite) benefits while the other species (host) suffers negative consequences. Lice or ticks (parasites) located on the human body (host) are an example of how lice obtain nutrition by feeding on the blood of the individual (host), causing the individual’s fitness to deteriorate and hurting the human body.