It will represent the change in temperature between midnight and 6, the correct option is C.
H(t) is the rate at which the temperature changes. So, if we integrate H(t), we will get the change of temperature.
In this case, we have:
[tex]\int\limits^6_0 {H(t)} \, dt[/tex]
This will give the change in temperature between 6:00 AM (represented by the 6) and midnight (represented with the 0).
So the correct option is C.
If you want to learn more about integration, you can read:
https://brainly.com/question/18760518