Why does the Environmental Protection Agency use a color chart to identify air quality?

Ease of understanding

Explanation:

In simple words, the use of colors for air quality index is majorly done by the authorities so that every individual whether educated or uneducated can understand it easily. Also it gives a clear and certain information when the chart is provided in colors.

The green color indicates good quality, the yellow color indicates moderate quality and the red color indicates the poor or danger level of air quality.

i dont have that book

answer is b.

  it is always the best policy to have good communication and good relations between individuals and, specially, between leaders of the countries. for this purpose, among others, there is a common place, the united nations, where the representants can present his and learn about the other country's policies.