What are invasive species?
a. nonnative species that are superior competitors
b. native species that prey on nonnative species
c. native species that have no predators
d. nonnative species that do not survive

A. Nonnative species that are superior competitors

A) a non-native species that is is superior to competing native species

Explanation:

Invasive species are non-native species that did not co-evolve with native species causing the introduced invasive species to have less controls and natural predators resulting in them being superior competitors that utilize resources in abundance and more effectively than native species, causing unbalance in the ecosystem due to native species being deprived of resources and not being able to survive or reproduce.