Answer: A. It provides her with a large amount of information about air pollution in New York City.
Explanation:
A comparative investigation is when data is collected in order to make a particular comparison.
With regards to the question, the student conducted a comparative investigation in order to test the hypothesis that different areas of New York City have different levels of air pollution.
The benefit of this study done by the students is that it will provide her with a large amount of information about air pollution in New York City. The area with the highest air pollution, what causes air pollution and other necessary information can be gotten.
Therefore, the option is A.