What is a key characteristic of green roofs regarding stormwater management?

Green roofs play a crucial role in stormwater management due to their ability to absorb and filter rainfall. This characteristic helps to mitigate runoff, which is the excess water that flows over impervious surfaces like concrete and asphalt during rain events. By retaining rainwater, green roofs not only reduce the immediate volume of runoff but also promote infiltration, allowing some of the water to return to the atmosphere through evaporation and transpiration.

Additionally, the vegetation and growing medium in green roofs act as a natural filter, which can improve water quality by capturing pollutants and sediment before they enter the stormwater drainage system. This function supports the overall goals of effective stormwater management, which include reducing flooding risk, preventing erosion, and improving water quality.

The other choices do not accurately represent the primary benefits of green roofs in terms of stormwater management or contain misleading information. The emphasis on the stormwater management capabilities of green roofs makes option C the most relevant and correct response in this context.