Final answer:
The cost-effective way to store rarely used data is through archived storage.
Step-by-step explanation:
The cost-effective way to store rarely used data is through archived storage. Archived storage is a data storage option where data that is not frequently accessed or modified can be stored for a long period of time. Unlike hot storage which is used for frequently accessed data or warm storage which is used for data that is accessed less frequently but still needs to be readily available, archived storage is designed specifically for rarely used data. It is a cost-effective solution as it typically provides lower storage costs compared to other storage options.