I would say graph C.
As the value of x increases, you first see that y increases.
So, your first assumption is that it should be A or B.
But then, it goes down to 2, but goes up again to 3. So, it cannot be increasing nor decreasing.
The closest is then C. If the line is at y = 3, then it fluctuates with +/- 1 from the actual value.