PLEASE HELP!!!

Which of the following relationships represents a function?
A.
x -6 5 -2 -2
y 8 6 8 7


B.
x -6 5 -6 7
y 8 8 14 7


C.
x -6 5 -3 10
y 8 6 14 8


D.
x -6 5 -2 5
y 8 6 8 7