PLZ I NEED HELP!
Which relation is a function

A.(-7,6) (6,-7) (-7,9) (10,3)

B. (5,-4) (-4,5) (-5,4) (4,-5)

C. (8,-5) (-5,8) (-5,-8) (-8,5)

D. (2,-3) (-3,2) (2,3) (-2,3)