Which of the Following Best Describes an Invasive Species

Which of the following best describes an invasive species?

A) An invasive species is any non-native introduced species,whether it becomes established or not.
B) Non-native species become invasive when they become established in a new area,taking over niches that were already occupied by native species.
C) Dispersal,even if anthropogenic,is a normal biogeographic process and,therefore,no cause of alarm.
D) Approximately 90% of all introduced non-native species become invasive species.
E) Invasive species,though non-native to a region,enrich the area in which they occur,adding to the overall biodiversity.