Which three data preparations should be made to retain high data quality in the new mode?

A Marketing Cloud admin is tasked with overhauling the data model for Enterprise. While the current data model is isolated to the email channel and there are plans to expand to both SMS and Push channels in the near future.

Which three data preparations should be made to retain high data quality in the new mode? Choose 3 answers.
A . Remove nonessential data for marketing purposes.
B . Identify and assign appropriate keys to tie records together.
C . Normalize data and fields to prevent redundancy.
D . Ensure all available data is included.
E . Ensure every data source has a sendable field.

Answer: A,B,C