When copying an object in Java, what is the difference between a shallow copy A$.$ A shallow copy duplicates only the object's reference variables, not the objects deep copy duplicates everything, including the objects referenced by the fields. B$.$ A shallow copy creates a brand new instance of the object's class with new data reuses the same class instance and keeps the original data intact. C$.$ A shallow copy is used for immutable objects and primitive types, whereas a de exclusively for mutable objects and complex data structures. D$.$ A shallow copy is a copy of the object's methods, while a deep copy is a copy o methods.