Which of the following is an example of an element of definition?

An element of definition in modeling refers to the fundamental constructs that define or describe entities and their behavior in a system. An activity exemplifies this concept because it represents a fundamental unit of work or a process in a model. Activities encapsulate specific functions or operations, making them crucial for outlining the behavior of a system.

In the context of modeling, options like flow property, part property, and connector serve specific purposes within the framework but are not elements of definition themselves. For instance, flow properties describe the characteristics of data flowing through a system, part properties define attributes of components, and connectors are used to illustrate relationships or interactions between elements. While these components are essential for creating comprehensive models, they do not encapsulate the core defining characteristics of behavior within the same context as activities do.