The Zebra Mussel Was Introduced into the Great Lakes, Where

The zebra mussel was introduced into the Great Lakes, where it has outcompeted other species and done economic damage. What is the most important reason that the introduced zebra mussels were so successful?

A) All introduced species are able to outcompete native species in this way.
B) Zebra mussel populations grew rapidly because they are photosynthetic and do not have to find food.
C) Zebra mussels can attach to boats and irrigation pipes, giving them more possible habitats than in their native range.
D) Zebra mussels were deliberately introduced into the Great Lakes, so humans helped to protect them until the population grew to a stable size.
E) Zebra mussels were able to exploit an ecological niche without their natural predators to control their numbers.