Option C will allow the customer to use their historical contact data to segment customers by the reachable contact channel preference, and prioritize the contact volume initially to the lowest cost channel. This will help reduce the overall cost of the campaigns.
Option D will help limit the communication volume by implementing a content preference management webapp and implementing contact pressure typology rules. This will ensure that contacts are only included in relevant campaigns and are not bombarded with unnecessary communications.

The architect should create a package of the affected entity, which includes the delivery meta data, such as the period and delivery validity, in the package definition. This will ensure that the original delivery properties are preserved and can be easily redeployed for testing. The package should also include other relevant information such as the entity definition, business rules, and workflow processes.
Additionally, it is good practice for the Architect to keep track of the changes made to the package and delivery properties through version control and configuration management. This will help to easily revert to a previous version of the package if needed.

A composite key is a combination of two or more columns used as a primary key for a table. This can help to reduce the number of joins needed in queries, which can improve performance.
Creating indexes on fields used within joins can also help to improve performance. Indexes are used to quickly locate data without having to scan the entire table. When a join is performed, the database engine can use the indexes to quickly find the matching rows in the tables, which can improve performance.
References:
Composite keys in database design: https://www.sitepoint.com/composite-keys-database-design/ Indexing in SQL databases: https://www.postgresql.org/docs/9.1/indexes.html