which mapping diagram represents a function from x → y?

Explanation:

Step1: Recall function definition

A function from $x$ to $y$ has each $x -$ value mapped to exactly one $y -$ value.

Step2: Analyze Option A

In Option A, each value in the set of $x$ values ($2,3,5,8$) is mapped to exactly one value in the set of $y$ values ($0,3,4,9$).

Step3: Analyze Option B

In Option B, the $x -$ value $2$ is mapped to both $4$ and $6$, so it is not a function.

Step4: Analyze Option C

In Option C, the $x -$ value $5$ is mapped to both $7$ and $8$, so it is not a function.

Step5: Analyze Option D

In Option D, the $x -$ value $2$ is mapped to both $4$ and $5$, so it is not a function.

Answer:

A. 2→0, 3→3, 5→4, 8→9