Answer:C. to inform people about the negative impacts of plastic pollution
Explanation:The author throughout the passage describes the negative impact of plastic and the types of plastic that pollute the environment. It's a descriptive report of the effects of plastic.
Why not A: The author never discusses good types of plastic, so we can rule this answer out.
Why not B: The author never goes so far as to say that it's the most harmful, or even to compare it to other pollutants (as the word "most" implies).
Why not D: The author is very informative. This isn't a persuasive essay appealing to emotions or logic, just a factual (if somewhat one-sided) description of the problem.
