Deploying QoS can solve the problem of user service quality in the process of network communication. Its purpose does not include?

Deploying QoS can solve the problem of user service quality in the process of network communication. Its purpose does not include?
A . Control the number of concurrent users
B . Regulating the traffic of the IP network
C . Avoid and manage network congestion
D . Reduce the loss rate of packets

Answer: A