Choose the best topic sentence from the four options below. Write the corresponding letter of your choice on the answer sheet.A. Statistics show that the negative effect of warmer nights on older people is twice that on younger people.B. Rising nighttime temperatures driven by climate change may harm human sleep, with the elderly most affected.C. A one- degree Celsius (摄氏度) increase in nighttime temperature may lead to three nights of interrupted sleep.D. The negative effect of warmer nights is most acute in summer, almost three times as high as that during any other season.
B
