PLEASE HELP ASAP
Which relation is a function?


A.

{(5, 5), (5, 9), (5, 15)}


B.

{(0, 3), (0, 9), (12, –4)}


C.

{(–5, 1), (4, 9), (6, 10)}


D.

{–2, 10), (–6, 10), (–2, 3)}