Answer:
A, C
Step-by-step explanation:
The lists of first numbers of the ordered pairs in each set are ...
A: 1, 5, 8 . . . . . . unique, this is a function
B: 1, 5, 5. . . . . . .not unique; not a function
C: 1, 49, 52 . . . unique, this is a function
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A function cannot have multiple outputs for the same input. For relation B, the input of 5 gives outputs of 'a' and 'c', so it is not a function.