In the maximization models, the objective function is alternatively named profit function. The logic behind this is the utmost goal of maximizing something is to gain a benefit or a “profit”. In the maximization models the value of Z needs to be increased as much as possible. An infinite number of iso-profit lines can be drawn for increasing values of Z. However, under the constraints of the model, the highest possible value of Z must reside in the feasible region.

As also understood from the information given, the statements in the options I, II and IV about the maximization models are correct, so the correct answer is D. The statement in the option III is not correct because of the fact that an infinite number of iso-profit lines can be drawn for increasing values of Z. However, under the constraints of the model, the highest possible value of Z must reside in the feasible region.