HUAWEI CLOUD ELB is a service that distributes traffic to multiple ECS instances and supports Layer 4 and Layer 7 forwarding protocols. When the seven-layer service is loaded, which of the following methods is mainly used to distribute traffic to ECS instances? (Multiple choice)
A . Really meaningful application layer content in the message
B . Distribution strategies and rules set in ELB
C . The destination IP address and port in the message
D . Source IP address and port in the message
Answer: AB