TOEFL Listening: ETS-TOEFL听力机经 - BUXN58J1113H339UP$

Why does a student mention the introduction of shrimp into a lake in Montana? A. To point out a possible danger of assisted migration B. To explain why certain species are good candidates for assisted migration C. To suggest that assisted migration can benefit several species at the same time D. To give an example of a new assisted migration program that is being considered