Which of the relations below is NOT a function A 15 25 35 45

Which of the relations below is NOT a function? A. {(-1,5), (-2,5), (-3,5), (-4,5)} B. {(0,-2), (1,0), (-1,-3), (0,-1)} C. {(6,-2), (-4,6), (-2,4), (1,0)} D. {(2,5), (3,6), (4,7), (5,8)} E. None of the above.

part B is not a function

Because 0 has two images -2 & -1 that is \"0\" is mapped to two values -2,-1