Explanation
According to the Multi-cluster Warehouses documentation, auto-suspend is a feature that allows a warehouse to automatically suspend itself after a specified period of inactivity. For a multi-cluster warehouse, auto-suspend applies to the entire warehouse, not to individual clusters. Therefore, auto-suspend occurs when the minimum number of clusters is running and there is no activity for the specified period of time. The other options are incorrect because:
*A. Auto-suspend does not occur when there has been no activity on any cluster for the specified period of time. This would imply that each cluster has its own auto-suspend timer, which is not the case. The warehouse has a single auto-suspend timer that is reset by any activity on any cluster.
*B. Auto-suspend does not occur after a specified period of time when an additional cluster has started on the maximum number of clusters specified for a warehouse. This would imply that the auto-suspend timer is affected by the number of clusters running, which is not the case. The auto-suspend timer is only affected by the activity on the warehouse, regardless of the number of clusters running.
*D. Auto-suspend does apply for multi-cluster warehouses, as explained above. It is a feature that can be enabled or disabled for any warehouse, regardless of the number of clusters.