Question

human - made structures such as roads, buildings, and other infrastructure tend to absorb and re - emit more heat than do natural landscapes. hence, urban areas, where human - made structures are highly concentrated, become \heat islands\ of higher temperatures relative to greener, less developed outlying areas. residents of urban heat islands (uhis) tend to use more air conditioning than residents of suburban and rural areas, thereby consuming more energy and disproportionately contributing to air pollution. to mitigate these effects, many urban communities are exploring natural cooling solutions, such as green roofs - vegetative layers grown on rooftops that both absorb air pollutants and reduce the temperature of the roof surface and surrounding air.
which choice best states the main idea of the text?
choose 1 answer:
a the relatively high temperatures of urban heat islands lead to increased energy consumption and pollution, so many urban communities are considering natural cooling solutions.
b the primary cause of urban heat islands is the lack of vegetation in cities, which can be easily remedied by planting more trees and creating new communal green spaces, such as green roofs.
c urban heat islands are cities that experience higher temperatures relative to surrounding rural areas, as human - made structures like roads and buildings tend to absorb and re - emit more heat than do natural landscapes.
d green roofs have become increasingly popular in cities, as they offer a natural solution to both the increased air pollution and the relatively high temperatures of urban areas.

Explanation:

The text first explains that urban heat islands (UHIs) have higher temperatures due to human - made structures, which leads to more energy consumption (more air conditioning) and pollution. Then it mentions that many urban communities are exploring natural cooling solutions like green roofs. Option A captures this cause - effect (high temperatures leading to energy consumption and pollution) and the response (natural cooling solutions) structure.
Option B is incorrect because the text does not state that the lack of vegetation is the "primary cause" of UHIs. Option C only describes what UHIs are (higher temperatures due to human - made structures) but does not mention the consequences (energy consumption, pollution) and the solution (natural cooling). Option D focuses too much on green roofs as the solution without properly connecting the cause (high temperatures of UHIs leading to energy consumption and pollution) which is a key part of the text's main idea.

Answer:

A. The relatively high temperatures of urban heat islands lead to increased energy consumption and pollution, so many urban communities are considering natural cooling solutions.