Answer:
The answer to your question is the second option
Explanation:
To determine if a set of ordered pairs represents a function the value of the x-coordinate must not be repeated.
a) This option is incorrect because "-1" repeated twice
b) This is the correct option because the x-coordinate does not repeat
c) This option is incorrect because "-1" is repeated twice and "1" is also repeated twice.
d) This option is incorrect because the x-coordinate "1" is repeated in all the sets.