Wastewater treatment systems in many communities have not kept up with
urban growth, and rainstorms carry polluted water directly into the rivers.
What is the strongest argument for addressing this problem with state or
federal regulation instead of at the local community level?
A. The same rainstorm may fall in many places, so several cities
have problems.
B. City governments change from year to year, but water is a long-
term issue.
C. The same river flows past many cities, so one city's decisions
affect others.
D. Cities do not have the expertise to decide how to make their water
cleaner.