Which relation is not a function?

[Control] A. ((6.5). (-6, 5). (5.-6)

[Control] B. ((6,-5). (-6, 5). (5.-6))

[Control] C. ((-6,-5). (6.-5. (5.-6) }

[Control] D. ((-6,5). (-6.-6). (-6.-5))

D.

Step-by-step explanation:

That would be D because there is a repetition of x = - 6.

-6 maps to - 6, 5 and - 5 which is not allowed in a function.

Functions can be one-to-one or many-to-one but not one-to-many.