Determine which of the following sets of ordered pairs represents a function. {(−2,−10),(16,−10),(−15,−10),(−13,− 10)} {(−6,−10),(−6,−15),(−6,15),(−6,7)} {(−15,−10),(16,−6),(−15,15),(16,7)} {(−2,−10),(16,−15),(−13,15),(−2,7)}