Answer:
c
Explanation:
A relation between two sets is a collection of ordered pairs containing one object from each set. If the object x is from the first set and the object y is from the second set, then the objects are said to be related if the ordered pair (x,y) is in the relation.
A function is a relation from a set of inputs to a set of possible outputs where each input is related to exactly one output.
The graph represents the relation, but not a function.
This is relation, because it defines the rule for each some such, that the ordered pair (x,y) lies on the graph.
This is not a function, because for all input values of x (excluding x=3) we can find two different output values of y.