Two functions, function A and function B, are shown below: Function A

x y
7 14
8 16
9 18

Function B

The first quadrant of a coordinate grid is shown from 0 to positive 8 on both axes at intervals of 1. The title is Function B. Only the even numbers are shown on the scale. A line is drawn by connecting the points on ordered pairs 1, 3 and 2, 6 and 3, 9.

Which statement best compares the rate of change of the two functions?
The rate of change of both functions is 2.
The rate of change of both functions is 3.
The rate of change of function A is greater than the rate of change of function B.
The rate of change of function B is greater than the rate of change of function A.