In which choice is y a function of x? А
(1,3), (3, 4), (4, 5), (5, 6)
B
(2,0), (2, 3), (4, 5), (6, 7)
(2,5), (4,8), (6, 10), (2, 12)
C
(6,2), (4, 1), (6, 8), (8, 10)

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.