Which of the following sets of ordered pairs represents a function

A.{-8,14) , (-7,-12) , (-6,-10) ,( -5,-8)}

B. {(-4,-14) , (-9,-12) , (-6,-10), (-9,-8)}

C {(8,-2) , (9,-1),(10,2),(8,-10)}

D. { (-8,-6) , (-5,-3) , (-2,0),(-2,3)}