Step-by-step explanation:
The range of a function is basically the y-value of the lowest point in the function and the y-value of the highest point in the function.
In the graph shown, the lowest point is (0,1) and the highest is (3, 4). Their y-values are 1 and 4 respectively.
The points are not connected in a straight line. Instead, they are separate points with a difference of 1 in their y-values.
So the answer is {1, 2, 3, 4}