The correct answer is:
A. The amount of open land in the U.S. decreased.
Explanation:
1. Urbanization, which is the growth of cities as the population increases, leads to the development of urban areas and the expansion of cities.
2. As cities grow, they require more land for housing, infrastructure, and commercial purposes, leading to the conversion of open land into urban areas.
3. This process results in the decrease of open land available for agriculture, recreation, and natural habitats.
4. Therefore, one of the outcomes of urbanization is the reduction in the amount of open land in the United States.