The range of the function graphed is in option D
What is range of a function?
The range of a function is the set of all possible output values it can produce.
The range is the set of all values that the output can take on as the independent variable (input) varies across the domain of the function.
This is seen in the y-axis. examining the graph, one can see that the range is from 1 to 7. represented as
1 ≤ y ≤ 7