In Huawei cloud computing environment, which description about the role of load balancer is correct? (Multiple choice)

In Huawei cloud computing environment, which description about the role of load balancer is correct? (Multiple choice)
A . Load Balancer can achieve load balancing between servers, thereby improving the response speed and overall performance of the system
B . Load Balancer can monitor running status of the server, timely find abnormal running server, and transferring access request to other server can work normally, so as to improve the reliability of the server group
C . After using load balancer, can flexibly add server according to the development of business, the expansion ability of the system was improved at the same time simplify the management
D . Load Balancer itself needs to achieve their own high availability

Answer: ABCD