Which two techniques should be used for smooth interoperability now and in the future?

Universal Containers would like to remove data silos and connect their legacy CRM together with their ERP and with Salesforce. Most of their sales team has already migrated to Salesforce for daily use, although a few users are still on the old CRM until some functionality they require is completed.

Which two techniques should be used for smooth interoperability now and in the future?
A . Replicate ongoing changes in the legacy CRM to Salesforce to facilitate a smooth transition when the legacy CRM is eventually retired.
B. Specify the legacy CRM as the system of record during transition until it is removed from operation and fully replaced by Salesforce.
C. Work with stakeholders to establish a Master Data Management plan for the system of record for specific objects, records, and fields.
D. Do not connect Salesforce and the legacy CRM to each other during this transition period, but do allow both to interact with the ERP.

Answer: B,C