The Clean Air Act is a United States federal law designed to control air pollution on a national level. The 1955 Air Pollution Control Act was the first U.S federal legislation that pertained to air pollution. The first federal legislation to actually pertain to "controlling" and monitoring air pollution was the Clean Air Act of 1963. The 1990 amendments addressed acid rain, ozone depletion, and toxic air pollution, and increased enforcement authority. Currently, counties are rated on the number of pollutants that exceed the acceptable level. The chart below show how these counties were rated.

Question

Which of the following is a hypothesis about why counties in the chart do not meet air quality standards established by the Clean Air Act?
A.
The majority of the counties that do not meet air quality standards correlate with the location of a major city which due to high human population contributing to air pollution.
B.
The majorities of counties that do not meet air quality standards correlate with cities that do not have a recycling program which will result in a high rate of pollution.
C.
The majorities of counties that do not meet air quality standards correlate with large cities that don’t have public transportation and therefore have more air pollution due to the large number of cars and their emissions.
D.
The majorities of counties that do not meet air quality standards correlate with large cities that do not monitor their air pollution from large factories which will result in a large amount of air pollutio

Answer 1

The best hypothesis about why counties in the chart do not meet air quality standards established by the Clean Air Act is:

A. The majority of the counties that do not meet air quality standards correlate with the location of a major city which due to high human population contributing to air pollution.

This hypothesis is broad and considers the general relationship between population density and air quality, suggesting that higher human populations typically lead to increased pollution due to more vehicles, industrial activity, and overall human activity. The other options, while potentially valid considerations in specific cases, are more narrow in focus and may not capture the broader underlying issue of population density as a primary factor in air quality issues across multiple counties.