Use the horizontal line test to identify the relation whose inverse is a function. I’ll send the graphs to choose from. Here are the first two to choose from

By the horizontal line test, If any horizontal line intersects the graph of a relation more than once, then the relation does not have an inverse.
From the given graphs:
In each of the graphs, a horizontal line is drawn. Two points are circled in three of the graphs to show that the inverse does not exist and is not a function.
The correct graph is enclosed in blue.