Answer:
c. problem, never, end.
Step-by-step explanation:
Emphasizing is done when there is the need to focus, to stress or make it more relevant or highlight an important point. This is done so that whatever is emphasized is the important point in a sentence or passage. So, we emphasize a certain point or issue when we want to stress its importance.
In the given sentence, the main emphasis will be on the terms "problem", "never" and "end". These words are emphasized to make the issue of plastic waste seem more problematic or dangerous, to emphasize the pollution issue. So, if these three words are emphasized, then the readers can understand the importance of how dangerous plastic waste is.
Thus, the correct answer is option c.