Which representations display nonlinear functions? Check all that apply.

On a coordinate plane, a line with negative slope goes through points (0, 1.5) and (2, 1).
On a coordinate plane, a parabola opens up.
A 2-column table with 4 rows. Column 1 is labeled x with entries 20, 21, 22, 23. Column 2 is labeled y with entries negative 1, negative 1.5, negative 2, negative 2.5.
A 2-column table with 4 rows. Column 1 is labeled x with entries negative 12, negative 11, negative 10, negative 9. Column 2 is labeled y with entries 7, 11, 14, 17.