According to the diagram, which statement describes the property db?

Consider the following diagram:

According to the diagram, which statement describes the property db?

A. The property db is a primary key

B. The property db is a static property.

C. The property db is inherited from a superclass.

D. The property db is important and is emphasized by the modeler with an underline.

View Answer

Answer: B

Explanation:

In UML, a static property is one that belongs to the class itself rather than any instance of the class. In UML diagrams, static properties are denoted by underlining the property name.

Now, let’s review the options:

A. There is no UML notation in the diagram that specifies whether the property db is a primary key.

Primary keys are a database concept and UML does not have a standard way to denote them.

B. The property db is underlined, which indicates that it is a static property. This is the correct UML notation for depicting a class-level attribute.

C. There is no indication in the diagram that db is inherited from a superclass. Inherited properties typically are not underlined (unless they are also static), and there is no superclass shown in the diagram.

D. Underlining in UML does not signify importance or emphasis by the modeler, it indicates that a property is static.

Therefore, the answer is B: The property db is a static property. This is based on standard UML notation as outlined in the UML 2.5 Specification by the Object Management Group (OMG), which dictates that static members (attributes or operations) are underlined in class diagrams.