Which of the following Alibaba Cloud products need to be considered to use if you want to build an elastic computing cluster to provide web service together and also with dynamic data and static data separately stored

Which of the following Alibaba Cloud products need to be considered to use if you want to build an elastic computing cluster to provide web service together and also with dynamic data and static data separately stored
A . ECS
B . SLB
C . RDS
D . OSS
E . KMS

Answer: A,B,C,D