Which two statements regarding ECS compliance are true? (Select 2)

Which two statements regarding ECS compliance are true? (Select 2)
A . Applies only to a namespace containing either CAS or S3 buckets
B . Must be enabled when creating a namespace
C . Applies only to a namespace containing both CAS and S3 buckets
D . Can be enabled on an existing bucket
E . Must be enabled when creating a bucket

Answer: AB