Question

If you wanted to find out how many New Yorkers suffer from asthma, which of the following would be the best resource?

Answer 1

I think you missed the options in the questions but anyway.
If you want to know about the asthma  people in the New York city then you can collect information from every hospitals in the city but it is rather a difficult method.
There are numbers of international agencies conducting research on number of people suffering the asthma in the You can contact them and got you desirable information.
Also, you can contact and request the respect government authorities to give  you the information for you study purposes.

Answer 2

Asthma is a respiratory problem and is related to the lungs. Although both adults and children can be affected by asthma, it is more prevalent among children.

The most reliable source to how many New Yorkers suffer from asthma is to contact the Center for Disease Control. You can also check the Department of Health website for the state (https://www.health.ny.gov/diseases/asthma/) for more information about asthma.