The following ordered pairs (x, y) define the relation q. is q a function?

{(-2, 0), (-1, 1), (0, 0), (1, -1)}

a) no, because there is more than one x value for some y values

b) yes, because there is exactly one x value for every y value

c) no, because there is more than one y value for every x value

d) yes, because there is exactly one y value for every x value