Jenny measured the temperature of the water in a beaker, set the beaker aside, and then measured the temperature again after an hour. If the initial temperature of the water was 30°C and the final temperature was 20°C, which of the following could be the temperature of the surrounding air?
A. greater than 30°C
B. greater than 25°C but less than 30°C
C. less than 25°C but greater than 20°C
D. less than 20°C