Determine which relation is a function.
A. (0, 1), (1, 1), (2, 3), (3, 4), (4, 5)
B. (0,0), (0, 1), (1, 0), (2, 2), (3, 3)
C. (-2, 1), (0, 3), (-2, 2), (4, 1), (1, 4)
D. (-3,2), (1, 4), (0, 0), (2, 3), (-3, 5)