How can you add extension fields to a standard business object? NOTE: There are 2 correct answers to this question.

How can you add extension fields to a standard business object? NOTE: There are 2 correct answers to this question.
A . Create an element in an extension business object (xbo).
B . Create a field by using key user tools.
C . Create a new field on an embedded component.
D . Create a field in a custom business object.

Answer: A,C