As the Marketing Cloud admin plans to expand the data model to include SMS and Push channels, it's important to prepare the data model for high data quality:

A. Remove nonessential data for marketing purposes: This helps streamline data management and ensures the data model is not cluttered with irrelevant information, making it easier to manage and use.

B. Identify and assign appropriate keys to tie records together: Proper key management ensures that different data sources can be linked effectively, facilitating a unified view across different marketing channels.

C. Normalize data and fields to prevent redundancy: Normalization reduces data redundancy and inconsistency, which is essential for maintaining data integrity and efficiency in a multi-channel environment.