1. In which set of ordered pairs is y a function of x?
A. {(1, 2), (0, 1), (0, 2), (1, 1)}
B. {(4, 1), (3, 1), (2, 1), (1, 1)}
C. {(1, 4), (1, 3), (1, 2), (1, 1)}
D. {(2, 5), (3,6), (6,5), (2, 7)}

Please help :(