Which statement correctly describes typical elements in a class diagram and how visibility is shown?

Which statement correctly describes typical elements in a class diagram and how visibility is shown?

• A. Only class names are shown; visibility is not represented.
• B. Classes and interfaces, attributes, methods, and relationships; visibility markers +, -, # indicate access level.
• C. Sequence relationships are shown as arrows with labels.
• D. Diagrams represent data flow; visibility is indicated by color.

Answer: (B)

In UML class diagrams, you typically represent the structure of a system by including classes (and interfaces), their attributes, and their methods, along with the relationships that connect them (such as associations, generalizations, and dependencies). Visibility is shown directly on each member using the markers +, -, and # to indicate public, private, and protected access. This setup lets you see what data a class holds, what operations it can perform, and how it interacts with other types. The other options describe different diagram kinds or oversimplified views: sequence diagrams use arrows to show message flows, data-flow diagrams aren’t standard UML for visibility, and showing only class names omits essential details like attributes and methods.

In UML class diagrams, you typically represent the structure of a system by including classes (and interfaces), their attributes, and their methods, along with the relationships that connect them (such as associations, generalizations, and dependencies). Visibility is shown directly on each member using the markers +, -, and # to indicate public, private, and protected access. This setup lets you see what data a class holds, what operations it can perform, and how it interacts with other types. The other options describe different diagram kinds or oversimplified views: sequence diagrams use arrows to show message flows, data-flow diagrams aren’t standard UML for visibility, and showing only class names omits essential details like attributes and methods.