Which relation is a function?



 
A.
(0, –45), (–45, –13), (18, –45)


 
B.
(33, –11), (23, 18), (23, –9)


 
C.
(8, 48), (8, 55), (9, 60)


 
D.
(–13, 30), (30, 19), (–13, 39)