The ordered pairs in the sets shown below are of the form (x,y). In which set of ordered pairs is y a function of x?
{(0,2), (0,4), (4,0)}
{(7,-1), (7,-2), (7,-3)}
{(1,3), (2,4), (3,5)}
{(-6,12), (1,8), (1,13)}
Each of the following tables contains elements of an (x,y) relationship. Which table contains four points that cannot lie on the graph of a function x?