Factories in the Midwest Spew Out Oxides of Nitrogen and Sulfur

Multiple Choice

Factories in the Midwest spew out oxides of nitrogen and sulfur that fall as acid rain in the Northeast, and Northeastern states can do nothing about it. This is an example of

A) why federalism is often viewed as a positive feature of American government.
B) a spill-over effect in the absence of consistent national standards.
C) a state government mandate.
D) an issue of federal sovereignty.
E) the necessity for state innovation in public policy.