The table below shows the value of a function. Which best describes the function, based on the average rates of change?

A.
The function is linear because the average rates of change are all the same, 4.

B.
The function is linear because the average rates of change are all the same, 2.

C.
The function is not linear because each average rate of change is 4 times the previous rate of change.

D.
The function is not linear because each average rate of change is 2 times the previous rate of change.