contact other schools within the state study science textbooks in the library look for current acid rain studies on the Internet examine soil samples taken at different locations
I gave my students this multiple choice question: Mrs. Garry's class wants to know if their area has more acid rain than other parts of the state. Which would be the best way for them to begin research?

Only one answer is correct among these 4 choices:
- contact other schools within the state
- study science textbooks in the library
- look for current acid rain studies on the Internet
- examine soil samples taken at different locations

Could you tell me which one is correct?

look for current acid rain studies on the Internet