What is mandatory to create in your planning area for the setup of reference product(s) to work?

You are modeling the introduction of a new product using Lifecycle Planning functionality in SAP IBP.

What is mandatory to create in your planning area for the setup of reference product(s) to work? Note: There are 2 correct Answers to this question.
A . Planning objects for the new product
B . Definition of an attribute representing the product ID
C . Definition of Actual Sales business meaning for one key figure
D . Definition of an attribute representing the product description

Answer: A, B