Which set of ordered pairs (x, y) could represent a linear function?
A = {(0,7), (1,5), (2, 2), (3,-1)}
B = {(3,5), (5,2), (7,-1), (8,4)}
C= {(0,7), (1,3), (3,-1), (5,-5)}
D = {(-3,2), (-1,4), (1,6), (3,8)}