Question

http://curriculum.kcdistancelearning.com/courses/ALG1x-HS-A06/a/exams/4-EXAM4/graph_1.gif
What is the domain of this graph?
(Points : 2)
{-2, -1, 0, 1, 2, 3 }
{-2, -1, 0, 1, 3}
{-4, -1, 1, 3,}