I was not sure what type of problem this would be so I put what i thought was close.

Which of the following relations represents a function?
a. (0,4) (0,-3) (1,-2)
b. (1,1) (1,2) (1,3)
c. (2,-1) (2,1) (2,3)
d. (-1,2) (1,2) (3,2)