Which of the following statements identifies a difference between optimization in levels and optimization in? differences?

A. Optimization in levels calculates the change in net benefits when switching from one alternative to? another, whereas optimization in differences calculates the net benefits of different alternatives.

B. Optimization in levels compares only the benefits from different? alternatives, whereas optimization in differences compares only the costs of different alternatives.

C. Optimization in levels compares only the costs of different? alternatives, whereas optimization in differences compares only the benefits of different alternatives.

D. Optimization in levels calculates the net benefits of different? alternatives, whereas optimization in differences calculates the change in net benefits when switching from one alternative to another.