Question

Which is not a function?

The set of ordered pairs: 8 comma 5, 3 comma 8, 5 comma 2, and 8 comma 3.
A mapping diagram is shown. The domain column contains the numbers 4, 9, ten, and twelve. The range column contains the numbers 1, 3, and 6. A line connects 4 and 6. A line connects 9 and 1. A line connects ten and 3. A line connects twelve and 6.
A table of x and y-values. When x is 7, y is 9. When x is 4, y is 8. When x is 2, y is 2. When x is 1, y is 6.
The set of ordered pairs: 6 comma 6, 4 comma 4, 9 comma 9, and 1 comma 1.