Which ordered pair represents y as a function of x?

A. {(−2, 0), (−1, 0), (−1, 1), (0, 2)}
A. {(−2, 0), (−1, 0), (−1, 1), (0, 2)}

B. {(0, 1), (1, 3), (2, 5), (3, 7)}
B. {(0, 1), (1, 3), (2, 5), (3, 7)}

C. {(−1, 4), (−1, 6), (0, 4), (1, 8)}
C. {(−1, 4), (−1, 6), (0, 4), (1, 8)}

D. {(9, 5), (9, −5), (11, 7), (11, −7)}