00:00

Question 51·Hard·Transitions

In urban areas, installing vegetation-covered "green roofs" has been shown to lower summertime building temperatures by reflecting sunlight and adding insulation. These cooler interior conditions can reduce reliance on air-conditioning systems, thereby cutting energy use. ______ a multi-year analysis of five northern cities revealed that buildings outfitted with green roofs actually consumed more energy during winter months, largely negating the summer savings.

Which choice completes the text with the most logical transition?