GMAT Critical Reasoning (CR) | Re: If the city goes on polluting the air at present rates, air quality an

If the city goes on polluting the air at present rates, air quality and visibility over the city will begin to suffer, rainwater may be polluted, and the city will contribute to the global problem of greenhouse emissions. Taxing every polluting commercial establishment per volume of polluted air or per particulate volume of greenhouse emissions will induce businesses to reduce the amount of pollution they emit; this charge will therefore protect the city's air.

Which of the following is an assumption