The graph of a non-invertible function $f$ is shown below. Also shown is a horizontal line which you can click and drag to different heights. If that line intersects the graph of the function $f\text{,}$ the point(s) of intersection will be shown. Next, the graph of an invertible function $g$ is shown.

1. According to these graphs, what is true about the graph of an invertible function?
   ? A horizontal line never intersects the graph more than once. A horizontal line may intersect the graph more than once.
2. According to these graphs, what is true about the graph of a non-invertible function?
   ? A horizontal line never intersects the graph more than once. A horizontal line may intersect the graph more than once.