Which of the following developments allowed cities to increase their geographical area in the late 1800s?

cable cars, and subways, was built, and skyscrapers began to dominate city skylines. New communities, known as suburbs, began to be built just beyond the city. Commuters, those who lived in the suburbs and traveled in and out of the city for work, began to increase in number.

Explanation:

cable cars, and subways, was built, and skyscrapers began to dominate city skylines. New communities, known as suburbs, began to be built just beyond the city. Commuters, those who lived in the suburbs and traveled in and out of the city for work, began to increase in number.

i think the answer is c, rivers.

explanation:

sometimes, borders fall along natural boundaries like rivers or mountain ranges. for example, the boundary between france and spain follows the crest of the pyrenees mountains. for part of its length, the boundary between the united states and mexico follows a river called the rio grande. the borders of four countries divide africa’s lake chad: niger, chad, cameroon, and nigeria.