Answer: D. The temperature fluctuates
Step-by-step explanation:
I will say this as a result of varying time of the day. Let me explain by comparing effects of day and night in cloud cover.
During the day:
As the cloud cover increases, the sun's heat (Ray) is repelled back to the cloud due to the covering present. Therefore, less of the sun's energy gets to the Earth's surface, this gives the earth a much cooler feeling and as a result the temperature is reduced.
During the night:
In this scenario, the opposite is the case as the cloud traps the heat which is supposed to be given off by the earth surface and re-emits it back towards the earth. This causes the Earth's temperature to become warmer, as a result increases the temperature.