a queuing system has three queues serviced with round-robin scheduling and one low latency queue that holds all voice traffic. round-robin queue 1 holds predominantly udp traffic, while round-robin queues 2 and 3 hold predominantly tcp traffic. the packets in each queue happen to have a variety of dscp markings per the qos design. in which queues would it make sense to use a congestion avoidance (drop management) tool?