Q12. Which relation is a function?

A
{(-1, 3), (-2, 6), (0, 0), (-2, -2)}

B
{(-2, -2), (0, 0), (1, 1), (2, -2)}

C
{(7, 4), (8, 8), (10, 8), (10, 10)}

D
{(4, 0), (4, 1), (4, 2), (4, 3)}