I'm pretty sure your answer should be D. Ship Ballast. Hope this helps! =^-^=
Answer:
D. Ship ballast
Explanation:
Zebra mussels are the invasive species that have adaptive features to allow them to invade the new ecosystems. They have floating larva that can be transported along with running water. Also, the adult form of zebra mussels have ability to attach themselves to various substrates such as boats and ship ballasts. The primary factor for introduction of the species in Great Lakes is attachment of the species to the ship ballast that enter the lake.
