What is a criterion used to assess changes in system behavior linked to the attainment of an end state?

The correct choice refers to the "Measure of Effectiveness," which is a criterion specifically designed to evaluate how well a system or operation is achieving its desired end state. It focuses on the broader impacts of actions within a system and how these actions contribute towards accomplishing overall objectives.

In military contexts, effective metrics can provide critical insights into whether strategic goals are being met and identify trends or shifts in behavior as a result of operational adjustments. Measures of Effectiveness tend to analyze outcomes in terms of their success in achieving mission-specific goals, ensuring that decisions made are data-driven and aligned with strategic intents.

Conversely, while "Assessment" can relate to evaluation processes, it is a more general term and does not specifically denote a system behavior linked to end states. "Measure of Performance" typically focuses on how well tasks are executed in terms of outputs and processes rather than the end goals themselves. "Patterns of Life" refers to the observed behaviors or movements of individuals or groups, but it does not serve as a direct measure of effectiveness in achieving an established end state.