A two variable linear program has the following characteristics: The objective function maximizes 7X1 + 12X2; Constraint 1 states that X1 1; constraint 2 states that X2 1; constraint 3 states that X1 0; constraint 4 states that X2 0. Which of the following statements is true about the linear program?

The optimal solution value is 19 and in the optimal solution, constraint 1 has slack variable = 0.

In the optimal solution, constraint 3 has a slack of 0.

In the optimal solution, constraint 1 has a slack of zero and constraint 2 has a surplus of 1.

The linear program has no optimal solution and it cannot be solved ever.