Identify the relation that is also a function.

A.
{(5, 6), (4, 5), (5, 8), (4, 0)}

B.
{(3, −1), (3, 1), (3, 0), (0, 2)}

C.
{(−2, 1), (−1, 2), (1, 4), (−3, −2)}

D.
{(6, 4), (6, −4), (10, 5), (10, −5)}