Explanation:

This scenario points directly to an issue with skills-based routing. Complaints from customers who speak other languages and a failure to assign cases to the correct agents strongly suggest that the routing logic is not properly matching cases that require specific language skills to agents who possess those skills.

A. Review Assigned Work:
This tab in Omni Supervisor shows work that has already been assigned to agents. While it can give some insight into what agents are working on, it won't show why cases with specific language requirements are not being routed correctly in the first place. The problem is in the assignment, not in the work that has been successfully assigned.

B. Review Queues Backlog:
This tab shows work items waiting in a queue to be picked up by an agent. If the routing is failing to assign language-specific cases, they might be stuck in a generic queue, but this view doesn't directly explain why they are stuck. It would show that there's a backlog, but not that the issue is a skills mismatch.

C. Review Skills Backlog:
This is the most targeted and relevant view. The Skills Backlog tab in Omni Supervisor is specifically designed for skills-based routing. It shows a list of all work items that are waiting to be routed because no agent with the required skills is available or online. By reviewing this backlog, the service manager can immediately see if cases requiring specific language skills (e.g., Spanish, French) are piling up. This will confirm the diagnosis that the skills-based routing is not working as intended, and it will be the first place to look to see what skills are in high demand and whether there are enough agents assigned to them.

Reviewing the skills backlog provides the quickest and most direct insight into the root cause of the problem.