3. Which relation shown is not a function?
{(1,5), (3, 7), (4, 10), (11,2), (4,8)}
{(1, -1), (2, -2), (3, -3), (4,-4), (5,-5)}
{(4,5), (5, 7), (3, 1), (1,3), (6,8)}
{(14,5), (5,5), (3,5), (11, 5), (5,5)}