Which set of ordered pairs represent a function? {(2,6), (2, -5), (2,7), (2,5)}
{(4,0),(-10, -1),(-8,1),(4,9)}
{(3,5),(3, 10), (3, -9), (3, -5)
{(-6,8),(-6, -7), (-6,6),(-6, -2)
None of the above​