WOULD YOU MIND ______, PLEASE

68. According to the passage, the Urban Heat Island Effect is caused by the fact(s) that...a. cities are warmer than nearby rural areas b. building materials absorb more of the sun’s heat than organic surfaces c. building materials release the sun’s heat more quickly than organic surfaces A. a. only B. a. and b. only C. b. and c. only D. a., b., and c.