The constraints of a two-variable linear programming problem is stated here: X 1;Y 1;X + Y 9.

Which of the following statements regarding the (X, Y) points is NOT TRUE?

1. The optimal solution might be X=1, Y=8
2. The optimal solution might be X=4, Y=4
3. The optimal solution might be X=0, Y=9
4. The optimal solution might be X=8, Y=1
5. We need to know the objective function to make a better statement.
6. All of the above is TRUE