Which of the following relations is a function? a.{ (-2, 4), (-1, 3), (5, 2), (1, 4) } b.{ (1, 7), (1, 8), (2, 7), (3, 8) } c.{ (2, 4), (4, 6), (4, 8), (6, 4) } d.{ (5, 7), (6, 3), (8, 6), (5, 4) }

From the pairs of x,y, if the set has two "x" of the same value, that is, "x" repeats, or an x-repeat, then is NOT a function

so, the group that doesn't have any x-repeats, is a function, now let's check

Do you mean conversion factor?