Which set of ordered pairs below is a function?
I.{(3,3),(6,1),(2,3)} .................. II.{(4,7),(2,8),(4,2)} .............. III.{(9,6),(3,1),(7,3)}


(((((((A I only )))))))) ((((( B II only ))))))) ((((((( C III only)))))) (((D I and III))))