Step 1: Identifying the feasible region.
The constraints define a feasible region where the objective function \( Z = 5x + 8y \) must be minimized. The corners of the feasible region are key points where we can evaluate the objective function.
Step 2: Evaluating the objective function.
We evaluate \( Z \) at the corners of the feasible region. The points of interest are the intersections of the lines defined by the constraints. After calculation, the minimum value of \( Z \) is found to be 31.
Step 3: Conclusion.
Thus, the minimum value of \( Z \) is 31, which makes option (C) the correct answer.