Answer:
This relation is not a function.
Explanation:
Function
A relation is a function when each input (x-value) has a single output (y-value).
A function is one-to-one if each output (y-values) corresponds to exactly one input (x-values).
A function is many-to-one if some outputs (y-values) correspond to more than one (many) inputs (x-values).
In the given relation, one input value (x = 4) corresponds to two output values. Therefore, this relation is not a function.
(See attached Relation Arrow Diagram).