Answer: C, a set of coords is only a function if it passes the vertical line test
Step-by-step explanation:
This is essentially the vertical line test. No two sets can have the same x value because it will fail the vertical line test. In answer a, -4 correlates to two y values. It fails the line test
B easily fails the test just by visually looking at it. It fails the line test
C has different x values so this looks promising. It passes the line test
D has the number 5 correlating with multiple y values. It fails the line test
