Answer:The last one
Explanation:
A function has to return a unique value when given an argument. In the last set
} ( – 2 , 1 ) , ( 3 , – 4 ) , ( – 2 , – 6 )}
, the argument -2 is supposed to return both 1 and -6 : this is not possible for a function.
Step-by-step explanation:
