How can the administrator check if the network infrastructure prioritizes traffic from Device 1 and Device 2?

Refer to the exhibit.

A network administrator sets up prioritization for an application that runs between Device 1 and Device 2.

However, the QoS for the application is not what the administrator expects.

How can the administrator check if the network infrastructure prioritizes traffic from Device 1 and Device 2?
A . Run a packet capture on Device 2, run the application, and look in the packet capture for a high value DSCP in the IP header.
B . Set up RMON alarms on the switches that trigger when a high number of packets are dropped. Then, run the application and check for the alarm.
C . Clear interface statistics on the switches. Then, run the application and check the interface queue statistics for the switch-to-switch links.
D . Run a packet capture on Device 1, run the application, and look in the packet capture for a high value DSCP in the IP header.

Answer: A