Question

Which is not a function?

The set of ordered pairs: two comma five, three comma eight, five comma two, and eight comma three.
A mapping diagram is shown. The domain column contains the numbers 4, 9, ten, and twelve. The range column contains the numbers 1, 3, 5, and 6. A line connects 4 and 5. 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 one, y is four. When x is 2, y is 6. When x is 3, y is eleven. When x is 8, y is twelve.
The set of ordered pairs: 1 comma 6, 2 comma 3, 4 comma 2, and 5