Answer:
Increase of 2°F/h..... Option 4.
Explanation:
Here in the table time in hours is the independent variable (x) and temperature in °F is the dependent variable (y).
The initial temperature at x = 0 hour is 52°F and then the temperature increases by 2°F per one hour time spent.
Therefore, the temperature is increasing at a constant rate of 2°F per hour from an initial value of 52°F.
Hence, option 4 is correct.