What are the 3 key actions that should be done when data modeling in salesforce?

UC has a legacy client server app that as a relational data base that needs to be migrated to salesforce.

What are the 3 key actions that should be done when data modeling in salesforce? Choose 3 answers:
A . Identify data elements to be persisted in salesforce.
B . Map legacy data to salesforce objects.
C . Map legacy data to salesforce custom objects.
D . Work with legacy application owner to analysis legacy data model.
E . Implement legacy data model within salesforce using custom fields.

Answer: A,B,E

Author