Answer:
(A)
Step-by-step explanation:
In a function, each value of X is related to ONE y value.
To identify a function, check if the x values repeat. If they do not, then the relation is a function.
Answer A's domain is [4,5,6,7]. The x values do not repeat, so A is a function.
B, C, and D all have repeating x values in the domain.
