Which table does NOT represent a function?

x y
-2 -2
-1 -2
0 -2x y -2 -2 -1 -2 0 -2 ,

x y
-2 2
-2 -2
-1 1x y -2 2 -2 -2 -1 1 ,

x y
-1 1
0 0
2 -2x y -1 1 0 0 2 -2 ,

x y
-1 -1
1 1
2

This table is incomplete and cannot be determined if it represents a function or not without more information.