Final answer:
In case management systems, merging eight similar cases typically requires multiple operations as you can only merge two cases at a time. There's no requirement for a parent/child relationship or closing all activities to merge cases but this can vary with system policies.
Step-by-step explanation:
If you need to merge eight similar cases, the correct statement is that you can only merge two cases at a time. This means that you would have to perform multiple merge operations to consolidate all eight cases into one master case.
It is a common practice in case management systems, especially in customer relationship management (CRM) software, to limit the merge functionality to two records at a time to maintain data integrity and to give users the opportunity to review and select the correct master record. There is typically no requirement for cases to have a parent/child relationship or for all related activities to be closed before merging; however, those conditions can be specific to the software or organizational policies in use.