Answer: {-2, 1, 2, 3}
You list the y coordinates of each point to form the range. The range is the set of all possible y values of a relation or function. Toss out any duplicates. The order of items in a set doesn't matter, but convention is to list the values from smallest to larger.
Extra info: The domain is {-4, -1, 1, 2, 3} which is the list of x coordinates of the points shown.