29. Which of the following is a function?
A{(-2,4), (-1,5), (0,5), (0,6)}
C. (-3, 4), (-3,5), (-1,5), (0,6)}
B. {(-4,4), (-3,5), (-2,5),(-1,6)
D. {(-3,4), (-2,5), (-3,5),(0,6)} ​