A user creates two Virtual Private Clouds (VPCs) (VPC 1 and VPC 2) in the CN North-Beijing4 region, and two Elastic Cloud Servers (ECSs), ECS-A and ECS-B, respectively, in VPC 1 and VPC 2. The user then creates another VPC in the CN East-Shanghai1 region, and two ECSs (ECS-C and ECS-D) in that VPC as well. The user needs to enable communications between different ECSs, match different scenarios with corresponding solutions:

Which of the following operations can be performed on Relational Database Service (RDS) instances?
NAT Gateway provides network address translation between private networks and between private and public networks.
A user sets up a service website on Huawei Cloud Elastic Cloud Server (ECS) and uses Huawei Cloud Relational Database Service (RDS) on the backend to store service data. The database configuration is correct, but the website cannot communicate with the database. Which of the following can not be the cause of this issue?
Which of the following statements are true about the relationship between account and Identity and Access Management (IAM) users?
Which of the following statements is correct about dynamic resource scaling of Auto Scaling (AS)?
On Huawei Cloud, snapshots can be used to save Elastic Volume Service (EVS) disk data at specific points in time. If you delete an EVS disk, its snapshots will not be deleted.
An ECS group logically groups ECSs. ECSs in the same ECS group are created on the same physical server by default.
The underlying physical resources of an Elastic Cloud Server (ECS) can be shared between users, but those of a Bare Metal Server (BMS) are exclusive to a single user.
HUAWEI CLOUD Virtual Private Network (VPN) does not support communications between two Virtual Private Clouds (VPCs) in different regions.
Which of the following statements about Object Storage Service (OBS) versioning is incorrect?
Cloud Backup and Recovery (CBR) allows users to easily back up cloud resources, including Elastic Cloud Servers (ECSs), Elastic Volume Service (EVS disks), and Scalable File Service (SFS) file systems. Which of the following statements about CBR are true?
Compared with physical disks, which of the following are advantages of HUAWEI CLOUD Elastic Volume Service (EVS)?
Which of the following statements about Content Delivery Network (CDN) is incorrect?