The figure below depicts the hierarchy of ____ class.

The figure shows java.lang.Number declared as an abstract class (labelled "<abstract> Number") with subclasses Byte, Short, Integer, Long, Float, and Double. Character, Boolean, and Void are shown separately under Object as other wrapper classes.

• Abstract class: Declared with the abstract modifier and cannot be instantiated.

• Abstract methods: If a class defines one or more abstract methods, the class itself must be declared abstract.

• Subclasses shown: Byte, Short, Integer, Long, Float, and Double are numeric wrapper classes that extend Number and are shown as its subclasses in the diagram.

• Conclusion: The hierarchy depicted is of an abstract class (Number), so 'abstract' is the correct answer.