Which of the following graphs is not a function? click on the graph until the correct graph appears.

the second graph,

step-by-step explanation:

the first graph is a horizontal line below the x-axis.   this is a function, because it passes the vertical line test; a vertical line drawn anywhere on the graph will only hit one point.

the second graph is a circle.   this is not a function, because it does not pass the vertical line test.   a vertical line drawn through the circle will hit two points.

the third graph is an upside-down absolute value graph.   this is a function, because it passes the vertical line test; a vertical line drawn anywhere on the graph will only hit one point.