Answer :
The answer is D! Zebra mussels were accidentally introduced to the Great Lakes by a human, and they have spread like a disease, since nothing is there to eat them. They are also taking the resources that natural mussels use, because they do not have any enemies in the Great Lakes. (this is a very invasive species!) Also, did you know they are clogging all the drains? This is an economic DISadvantage. So therefore, D is not true
