Answer: A.
Explanation:
We know that a function is a special kind of relation between two variables x ( input value) and y (output value) such that each input corresponds to exactly one output.
From all the three graphs , the graph A. shows the relation where there is two values of y for a unique value of x=2.
Therefore, the graph A. is not representing the function.
Hence, the graph A. is a relation( non- function).