Which graph represents a function?
1, 2, 3, or 4

Answer:
The given graph is a function.
Step-by-step explanation:
There is only one given graph, and that graph is a function. In order to determine which graph is a function, conduct the vertical line test. Can a vertical line pass through the represented data set without crossing two y-values? (i.e. A 'sideways parabola' is not a function).