Select the correct answer.

Urban land is the land that makes up a city or town. These maps show how the land use in Baltimore, Maryland, changed from 1966 to 1992. The level of pollution in this region also rose during this period.

Based on this information, which of the following is a likely reason for the rise in pollution levels?
A.
decrease in water surface area
B. increase in urbanization
C.
increase in fertilizer usage
D.
decrease in construction and mining