Which conversion-specific tasks need to be performed during the preparation phase?

You are planning an SAP S/4HANA conversion .

Which conversion-specific tasks need to be performed during the preparation phase? There are 2 correct answers to this question.
A . Run the database migration to the SAP HANA database
B . Perform the migration of data into the new data structure
C . Check the compatibility of custom code with SAP S/4HANA
D . Apply the recommendations of the simplification list

Answer: C,D