Question

The graph of a function f(x) is shown below:

Answer 1

Count the dots plotted here.  There are four of them, right?  What are the x-coordinates of those four dots:  Answer:  {-1, 0, 1, 2}.  

Reject answers B and C because none of the four dots have x-coordinate -3.
Reject answer A because this set would not include x=-1 or x=2.