Which one of the following interspecies relationships has a negative effect on both species?

Since the options aren't given.

Parasitism. There are several types of biotic relationships that is occurring every single moment in the ecosystem and one is parasitism. In this scenario with human beings and mosquitos, this phenomenon of interaction is distinguished as parasitism where mosquitos draws blood that contains nutrients from the human tissue to use it as its source of food and then leaves harmful substances and bacteria in the human’s blood stream.