Answer: "D"
Step-by-step explanation: The mapping diagram shown here would not represent a function. When looking at a mapping diagram, there is one key thing we need to look for to identity if the relation is a function. We need to look and see if an input has two different outputs. When looking at the mapping diagram, the input (2) has two completely different outputs which makes this hard to interpret data. This means that the relation is not a function.
When dealing with mapping diagrams, remember that an input can only have one corresponding output and if it has more than one, then this would not represent a function.