A user cannot print from their PC to the local printer id:123456789. Which Cisco DNA Center Assurance tool should be used to diagnose the problem?

The correct answer is path trace. Path trace in Cisco DNA Center Assurance allows you to visualize the end-to-end network path between a source (the user's PC) and a destination (the printer), including all intermediate devices. This tool helps identify where connectivity issues or policy blocks might be occurring along the data path. Device trace focuses on a single device's configuration and operational state, which is too narrow for an end-to-end connectivity issue. ACL trace specifically checks if an Access Control List is blocking traffic, but a path trace would first confirm if the traffic even reaches the point where an ACL might be applied. Application trace is used for monitoring application performance and dependencies, not for diagnosing basic network connectivity between a PC and a printer.