A. Leverage Big Objects to archive case data and Lightning Components to show archived data.

Big Objects provide a scalable solution for storing large volumes of data in Salesforce without impacting the performance of standard objects. They are designed for high-volume storage and can handle millions of records efficiently, making them ideal for archiving historical case data.
Using Lightning Components to access and display the archived data from Big Objects allows users to seamlessly view historical information within the Salesforce UI, ensuring that user groups who need access to this data can retrieve it easily.
B. Leverage on-premise data archival and build integration to view archived data.

For organizations with stringent data retention policies or those who prefer to manage their archival solutions, leveraging an on-premise data archival system can be an effective way to offload historical data from Salesforce. This approach helps in managing Salesforce storage limits and performance.
Building integration between Salesforce and the on-premise archival system ensures that users can access historical case data directly from Salesforce when needed. This can be achieved through custom development or middleware solutions, providing a bridge between Salesforce and the external archival system....

A. Leverage big object (Option A): Big Objects are designed for handling large volumes of data efficiently. Using a big object to archive historical case data can help minimize storage issues, and leveraging Lightning components to display archived data provides an integrated and user-friendly approach.

C. Create a custom object (Option C): Creating a custom object to store case history is a viable solution. This allows you to maintain a structured record of historical cases while reducing the load on the standard Case object. Running reports on this custom object enables user groups to access historical data without impacting the performance of the primary Cases object.

Options B and D involve storing data outside of Salesforce, which might not be the most efficient solution, especially when there are native Salesforce features like big objects and custom objects that can address the archiving requirements more seamlessly.