The graph which represent a graph of a function is:
Graph A and Graph C
<h2>Step-by-step explanation:</h2>
We know that a graph of a function satisfies the vertical line test i.e. any line passing through the domain and parallel to y-axis should intersect the curve exactly once i.e. corresponding to each x-value there is exactly one y-value.
Hence, from the figure attached to the answer we see that the Graph which is a function is: