Which of the following relations is a function? {(1, 2), (1, 0), (-3, -4)}
{(1, 2), (3, 2), (1, 4)}
{(1, 2), (3, 2), (5, 2)}
{(1, 2), (-3, 2), (-3, 3)}

plzzzzzzzzzzz help me!!!!!!!!!!!!!!!