A: Use references when you can use, and use pointers when you have to.

References are generally preferred over pointers whenever you don't require "reseating". Usually this means that references are most useful in class's public interface. Typically references appear on the skin of an object, & pointers on the inside.

The exception to the above is where a function's parameter or return value require a "sentinel" reference a reference which does not refer to an object. Usually this is best done by returning/taking a pointer, & giving the NULL pointer this special significance (references must always alias objects, not dereferenced NULL pointer).

Note: Old line C programmers sometimes don't like references as they provide reference semantics which isn't explicit in the caller's code. However, after some C++ experience, one quickly realizes it is a form of information hiding, which is an asset instead of a liability. E.g., programmers must write code in the language of the problem instead of the language of the machine.