You are an enterprise application developer. You plan to design the component architecture of a new large-scale application. You need to design a component architecture to meet the following requirements: Class objects must consist of multiple aggregate objects.Multiple aggregate objects must be instantiated only through the object that is enclosed within the class.Certain aggregate objects must be directly instantiated by user code.Multiple aggregate objects must allow user code to override properties within the object.All class objects must be versioned together. What should you do?

A.
Use a nested class model for all classes.

B.
Use private classes for all aggregate objects.

C.
Use sealed classes for all aggregate objects.

D.
Use abstract class for all the classes contained in the component.