The graph of a function f(x) is shown below:
what is the domain of f(x)?
a. integers from −1 < x < 2
b. integers from −3 < y ≤ 3
c. integers from −3 ≤ y < 3
d. integers from −1 ≤ x ≤ 2

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

The answer is or,ur welcome