A & B are correct because the data must be aggregated and saved as records of custom object, and this can happen using batch apex or snapshots https://help.salesforce.com/s/articleView?id=sf.data_about_analytic_snap.htm&type=5
Data Loader won't aggregate the data (you will do it on excel each time) and with the export and import it's a lot of work
Salesforce Archiving feature doesn't exist (except for activities - Task and Event)

Combine Analytics Snapshots with a Purging Plan (Option B): This approach involves creating Analytics Snapshots to capture and store aggregated data trends over time. Once the snapshot is taken, the original detailed records can be purged, reducing the storage footprint. This method ensures that historical trend data remains accessible for reporting purposes, but without the overhead of storing every single record. The key here is to establish a regular schedule for creating snapshots and purging, ensuring that the data remains current and relevant.

Configure the Salesforce Archiving Feature (Option D): Salesforce offers an Archiving feature that can be used to move older records out of the main data storage. These archived records are still accessible but do not count against the storage limits. This solution is particularly effective because it maintains access to historical data without impacting the performance of day-to-day operations. Records that are accessed infrequently but still need to be retained for historical analysis are good candidates for archiving....