Comprehensive and Detailed Explanation from Exact Extract:
Encapsulation in ABAP OO and ABAP Cloud ensures that internal object details are hidden from outside consumers.
* A. Attributes can be changed through public methods # # Correct, because controlled access is provided through getter/setter or other methods.
* B. Attributes can be changed by the client program directly # # Incorrect, this violates encapsulation.
* C. Attributes cannot be changed # # Incorrect, they can be changed, but only via allowed mechanisms.
* D. Attributes can only be changed by the class itself # # Correct, ensuring business logic consistency.
This aligns with RAP behavior definitions (BDEF) where internal attributes are encapsulated and only manipulated through behavior implementation methods.
Verified Study Guide Reference: ABAP Objects Programming Guide - Encapsulation Principles.