Which of the following relations is a function?
OA. (0,4), (-3,2), (8, 1), (-7, 2)
OB. (0,0), (-3, 3), (8, 1), (-3,5)
OC. (0,4), (-3, 6), (0, 3), (-7, 2)
OD. (8, 1), (-3, 4), (0, 1), (8, 2)