Maria created a graph of b(t), the temperature over time. for the interval between t = 3 and t = 7, the average rate of change in her graph of b(t) is 8. which statement must be true?

For some strange reason, I'm not able to find the units of the '8'
at the end of the question, or the answer-choices after that.

It seems to me that the only thing we can tell with the given
information is that the temperature at t=7 was 32° warmer
than the temperature at t=3 .