On the hub, diagnose vpn tunnel list enumerates IPsec tunnels including ADVPN shortcut sessions, showing their names, selectors and state. This confirms which spoke-to-spoke shortcuts are currently established and active without inspecting individual security associations.
Why this answer
How to eliminate wrong answers
Option A is wrong because 'execute router clear bgp all' clears BGP sessions — it is a disruptive reset command, not a verification command, and does not show tunnel state. Option B is wrong because 'get system sdwan neighbor' displays SD-WAN neighbor/health-check information, not IPsec tunnel or ADVPN shortcut state. Option D is wrong because 'diagnose netlink interface list' shows kernel-level interface information and does not enumerate IPsec tunnels or their shortcut status.