Correct answer: A). Invasive species
An invasive species are those species that are not native to the ecosystem, but when introduced it can cause harm to the environment, economy or even human health. Invasive species may include plant, insect, fungus, fish, bacteria or eggs or seeds of an organism.
Zebra mussels are an invasive species that are known to consume a huge amount of plankton, as a result of that, they compete with fish and other aquatic life for food and they also clog pipes by forming colonies in it and disturb the whole aquatic ecosystem.
