The feasible region for the linear programming problem. \(\begin{aligned}\text{Maximize }z=9x_{1}&+7x_{2}\\ \text{subject to }x_{1}+2x_{2}&\geq 7\\ x_{1}-x_{2}&\leq 4\\ x_{1},x_{2}\geq 0\end{aligned}\) is:

Unbounded bounded closed none of these

Unbounded

Sketch the region