You can see that the answers(y) of f(x) were Subtracted by a factor of 2 to make the answers(y) of g(x). example: 9-2=7 81-2=79 when a number is added to or subtracted from a function the graph will make a horizonal or vertical shift. therefore C. is correct
If we compare f(x) and g(x) results for each X value, we can notice there is a constant difference of 2. Graphically this makes the graph to move down.