The EPA has established that the air quality in a city (measured in pollution units, so high numbers mean worse air quality) depends on the number of cars driven in the city (measured in thousands) according to the relationship I(x)=30+(5x277)^3/5 Currently there are 75,000 cars in a city, and the number is increasing by 4,500 / year. At what rate is the air quality changing?

• A. 2.157 points/year
• B. 2.257 points/year
• C. 2.357 points/year
• D. 2.457 points/year