D) Melissa added incorrectly. The correct answer is 5.5 degrees Fahrenheit.
Multiply 5 degrees by 5 hours.
5 * 5 = 25
The temperature rose 25 degrees from 5am to 10am.
Add -20.5 + 25.
-20.5 + 25 = 5.5
The temperature at 10am should be 5.5 degrees Fahrenheit.