Final answer:
When a method assigns a new value to an object's member through a reference parameter, it affects the caller, as the object is passed by reference and not by value.
Step-by-step explanation:
If a method assigns a new value to a member of an object it can access through an object reference parameter, this will indeed have an effect on its caller, assuming that the language being used is one that passes objects by reference (such as Java or C#). When a method receives an object reference as a parameter and it modifies the object's members, those changes will persist outside the method. This is because the method does not have a separate copy of the object; it has a reference to the original object that was passed in. Therefore, any changes made to the object's members through the reference will be seen by any other references to that same object.