Voice quality is bad due to high delay and jitter on a link. Which two actions will improve the quality  of voice calls？（）

A.Increase the queue size of the voice class.
B.Guarantee bandwidth during congestion to the voice class with a bandwidth command.
C.Increase the tx-ring of the egress interface.
D.Implement LLQ for the voice class.
E.Decrease the rx-ring of the egress interface.
F.Decrease the queue size of the voice class.