What is described in the class methods definitions?

The correct answer is focused on the concept of functionality as it relates to class method definitions in object-oriented programming. Methods in a class are intended to define actions or behaviors that can be performed on the data encapsulated within the class. This is aligned with the notion that methods provide the functionality required to operate on the data represented by the class attributes.

When defining methods, the primary aim is to implement specific operations, manipulations, or computations that the instances of the class can execute. This distinguishes them from attributes, which simply hold data, as well as from business rules that might govern how that functionality operates within a broader context.

In summary, class methods manifest the behaviors that objects of that class can exhibit, thereby encapsulating the functionality that is central to the class's purpose and design.