Which of the relations given by the following sets of ordered pairs is a function? {(1,2), ( – 4,8), ( – 3,5), (1, - 2), (7, 12)} {(5, 4), (4,3), (3, 2), (4, 5), (2, 1)}
{(6, 1), ( – 3, 1), (3,5), (2, 4), (- 1, 2)}
{(5, 4), (5, 6), (5,8), (5, 10), (5, 12)}