In order for something to be a function, it has to pass the vertical line test, atleast in the standard coordinate plane. This is because a single x value can’t correlate with two separate y values. So the first one is not and the second one is
The graph that Franco is Incorrect
It suppose to be from left to right
Answer:
B
Step-by-step explanation:
The best - well, only way- is to check a few points.
Namely -1 (unless your eyesight is really poor!), 0, 1, 2, and 3.

Now you can mark all these points in each graph (well, you could if they were on paper and not on a screen) and see which one of the lines passes through all of them. Spoiler alert, it's the B graph.
A represents
, B is the one you want, C is
and D looks like 