which set of ordered pairs in the form of (x,y) does not represent a function of x?
a. (0,2),(1,-1),(2,3),(3,-2)
b. (0,-2),(1,1),(2,3),(3,-2)
c. (0,2),(-1,-1),(2,-3),(3,2)
d. (0,2),(1,2),(1,-2),(3,2)