What is a member function?

A member function is specifically defined as a function that is a part of a class and has access to its data members. This capability means it can operate on the data associated with instances of the class, allowing for the manipulation of class attributes and responding to class-specific actions.

When a member function is invoked, it has an implicit reference to the object it operates on, which makes it capable of accessing both the public and private attributes of that class. This is an essential concept in object-oriented programming, as it encapsulates behavior in relation to the data it manages.

The other options might describe functions in different contexts but do not capture the essential characteristics of a member function within a class. For instance, a function defined in a separate file relates more to modular programming and file organization rather than object-oriented principles. Functions that can only be accessed by the class itself refer more to private functions but do not address the concept of integration with class data. Lastly, a function that returns the class name pertains to metadata rather than the member function's operational integrity within the class.