Which of the following best summarizes the author's thesis in the passage?
A
The heat produced by power plants often attracts congregations of marine life such as jellyfish.
B
Many disruptions that are attributed to human activity are actually triggered by natural causes.
С
Expanding populations of jellyfish are causing increasing problems in many parts of the world.
D
Predation by jellyfish poses a significant threat to commercial fisheries worldwide.
E
Jellyfish have recently developed adaptations that enable them to live in a wider variety of ocean environments.