On a sequence diagram, a lateral bar or vertical rectangle is used to represent:
A) messages sent between classes.
B) the time sequence of activities.
C) the focus of control, when an object is busy doing things.
D) the lifeline for the class or object.

Question

Quizplus · Accepted Answer

The lateral bar or vertical rectangle on a sequence diagram represents the focus of control, indicating when an object is actively executing a process or method.

On a Sequence Diagram, a Lateral Bar or Vertical Rectangle