Select the relations that are functions.
A. {(a, 1), (6, 1), (C, 1);
B. {(a, a), (a, b), (a, c)}
C. {(1, a), (2, a), (3, a)}
D. {(a, a), (b, b), (C, c)}
PLEASE HURRY I HAVE ONLY 3 MINUTES LEFT!!!!