{(6,0), (-7,2), (-4, -8), (9,2)} option 3
A function can't have multiple x values (input values) with different output values (y values). To be a function it needs to have different x values.
Analyzing them we can see that
Is the only ordered pair that represents a function, is {(6,0), (-7,2), (-4, -8), (9,2)}
Because It doesn't have repeating x values with different y values like the other ordered pairs:
for example:
{(6,8), (-4,2), (-7,4), (-7,8)}
we can see that we have( -7 ,4) and (-7,8), a repeating x value (-7) with different outputs (4 and 8)