The correct answer is A. Versa throughput troubleshooting documentation includes a specific section titled Check that Packets Are not Dropped by CoS. It states that if a CoS shaper or rate limiter is configured on the VOS device, it may drop packets when traffic exceeds the configured shaping rate. To check whether CoS is dropping packets, Versa recommends commands including show class-of-services interfaces brief and show class-of-services interfaces detail interface-name.

The detailed interface output displays traffic statistics such as TX packets, TX packets dropped, TX bytes, TX bytes dropped, and per-traffic-class drops. This is exactly the evidence needed to confirm whether shaping or QoS enforcement is causing the observed loss.

show alarms last-n 10 may reveal major events but will not provide per-interface CoS drop counters. show system uptime only indicates how long the system has been running. show cgnat tenants is relevant for NAT state and tenant CGNAT resources, not QoS drops.