Which of the relations given by the following sets of ordered pairs is a function? O {(1,2), (2, 3), (3, 4), (3, 3), (2, 2), (1, 1)}
O {(1, 1), (1,3), (1,5),(1,7), (1,9)}
O {(-2, 1), (7,5), (- 4,0), (3, 1), (0, -6)}
O {(2, - 7), (6,5), (- 3,9), (2,0), ( – 5,3)}