It mean benchmarks in out side of math
a criterion by which to measure something; standard; reference point
Answer: it would be the fourth one with the line going straight across the top
Step-by-step explanation: To use the vertical line test, take a ruler or other straight edge and draw a line parallel to the y-axis for any chosen value of x.
If the vertical line you drew intersects the graph more than once for any value of x then the graph is not the graph of a function.