which of the following does not negatively affect the health of a watershed? A. Surface runoff from roads, sidewalks, and roofs. B. Sewer overflow from combined sewer systems. C. Wilderness areas. D. Chemicals used on farmland.

A. Surface runoff from roads, sidewalks, and roofs

C. Wilderness areas.  will mostly likely not affect the health of watershed

Explanation:

Options A and C are not really harmful to the health of watershed, but chemicals used on farmlands and overflow from combined sewer systems can contaminate watershed adversely, which can be a major cause of the cholera outbreak (a water borne disease)