A recent study by the city council concluded that much of the pollutants affecting the health of city dwellers comes from the neighboring industrial areas.

1. much of the pollutants affecting the health of city dwellers comes
2. much of the pollutants that affect the health of city dwellers come
3. many of the pollutants affecting the health of city dwellers come
4. much of the pollutants that affect the health of city dwellers came
5. most of the pollutants affecting the health of city dwellers come

What is the OA?