Urban sprawl occurs when a. cities spread out into the existing countryside b. cities extend upward c. people leave cities to live in rural areas d. none of the above

Answer;

A. cities spread out into the existing countryside

Explanation;

Urban sprawl is the rapid expansion of the geographic extent of cities and towns, often characterized by low-density residential housing, single-use zoning, and increased reliance on the private automobile for transportation.

It is caused in part by the need to accommodate a rising urban population; however, in many metropolitan areas it results from a desire for increased living space and other residential amenities.

The end result is  increased energy use, pollution, and traffic congestion and a decline in community distinctiveness and cohesiveness.

c is the answer to this question. altitude affects the weather because air molecules evaporate.