Which set of ordered pairs does not represent a function?

the set of the ordered pairs twenty comma ten, ten comma twenty, negative twenty comma negative ten, and negative ten comma negative twenty.

the set of the ordered pairs fourteen comma twelve, ten comma eight, six comma four, and two comma zero.

the set of the ordered pairs negative seven comma negative five, negative six comma negative three, negative five comma negative one, and negative four comma one.

the set of the ordered pairs zero comma negative one, five comma negative two, ten comma negative three, and fifteen comm