To determine which point is not one of the vertices of the shaded region, we need to graph the system of inequalities and identify the vertices of the resulting polygon.
After graphing the system of inequalities, we can see that the vertices of the shaded region are:
- (0, 13.33)
- (16, 4)
- (12, 0)
- (0, 20)
Therefore, the point (25, 5) is not one of the vertices of the shaded region. Answer: OB. (25, 5)