Answer:
<h2>C. 5.2°F per month</h2>
Step-by-step explanation:
The average rate of change refers to the relation between these variables.
Specifically, this problem can be modeled by a linear function, where the slope is the average rate of change.
So, such rate can be defined as

Where
is the first pair and
is the second one.
In this case, the first pair is
and the second pair is
. Replacing these coordinates, we have

Which is expressed in Fahrenheit.
Therefore, the average rate of change is 5.2 °F.
This can be interpreted as "The temperature changes +5.2 °F each month between March 15 and June 15".