Which statement about ABAP classes is true?

The statement that classes can contain methods and attributes is true. In ABAP, classes serve as blueprints for creating objects and encapsulate both data and functionality. This means that a class defines attributes for storing data (often referred to as instance variables) and methods for implementing behaviors (functions) that operate on the data.

Attributes can be defined with different visibility levels, such as public, protected, or private, allowing for controlled access to the class's data. Similarly, methods can also have various access levels. The ability to include both methods and attributes is a fundamental aspect of object-oriented programming, allowing for comprehensive class definitions that facilitate modularity, encapsulation, and reuse.

Furthermore, each class can inherit attributes and methods from other classes, which contributes to the strength of inheritance in the ABAP programming model, enhancing the overall structure and organization of code. This inheritance capability, combined with the encapsulation of properties and behaviors, makes classes in ABAP a powerful tool for developers when building applications.