The image illustrates a building with a green roof – a roof that is covered in living vegetation. Green roofs help to solve one part of a complex problem. A
green roof increases the amount of carbon dioxide taken up in an urban area
and reduces the building's energy costs for heating and cooling.
Which problem are green roofs most likely helping to solve?
A. Urban worker safety
B. Environmental impact of paved surfaces
C. Reliability of power supply
O D. Public health issues