Mary is campaigning for improved air quality in her city. she is very concerned about carbon and methane outputs, but not phosphorous. why is
that?
a. she thinks phosphorous makes a positive contribution to air quality,
b. phosphorous is most commonly found as phosphate rock.
c. she doesn't know a lot about phosphorous.
d. she doesn't consider phosphorous to be a greenhouse gas.

D. She doesn't consider phosphorous to be a Green house Gas.

Explanation:

Green house gases are major cause of air pollution today.They are becoming a big concern day by day.These gases are contributing to overall rise in Earth's temperature leading to Global warming.Mary is campaigning to improve air quality.Phosphorus is not a gas and is not considered as a significant air pollutant.But Carbon dioxide and Methane are reported to be significant green house gases in atmosphere.So, Mary is very much concerned about Carbon dioxide and Methane Outputs.

The answer is constant.