Which of these relations is NOT a function?
{(1,2),(2,3),(3,4)}\{(1, 2), (2, 3), (3, 4)\}{(1,2),(2,3),(3,4)}
{(1,1),(2,1),(3,1)}\{(1, 1), (2, 1), (3, 1)\}{(1,1),(2,1),(3,1)}
{(1,2),(1,3),(2,4)}\{(1, 2), (1, 3), (2, 4)\}{(1,2),(1,3),(2,4)}
{(0,0),(5,5),(10,10)}\{(0, 0), (5, 5), (10, 10)\}{(0,0),(5,5),(10,10)}