Mark this Determine which graph defines y as a function of x. (4, 7) 6 5 4 (1, 3) ( 5 , 3 ) 3 ( 2 , 3 ) 2 (3, 2) O -2 -1 2 3 6 6 -5 -4 -3 -1 -2 -3 -4 -5