11. Which set of ordered pairs represents y as a function of x?
A. {(-4,-3), (-4,-2), (-3,-3), (-3,-2)}
B. {(2.0), (4,0), (4,2), (6, 2)}
C. {(6,-2), (6.0), (6,2), (6,4)}
D. {(0, 0), (2, -4), (4, -8), (6,-12)}