Answer:
H.
Step-by-step explanation:
something is represented as a function when none of the inputs (x) repeat, but the outputs (y) change. the graph for letter G has repeating x values, but the y values don't change when an x repeats. however, the graph for letter H has repeating inputs (x), but the outputs are different, even with the same input.
that's why parabolas aren't functions (if you know what those are).
hopefully that helps and isn't too confusing! if you need anything else, let me know! :)
