The Introduction of the Zebra Mussel from the Caspian Sea

The introduction of the zebra mussel from the Caspian Sea to the Great Lakes was:

A) Intentional,to help clean the Great Lakes
B) Accidental,it was brought over on the hulls of fishing ships
C) Intentional,to provide food for an endangered fish
D) Accidental,from the ballast water from ships
E) Intentional,to provide food for humans