Which of the following statements about network ACLs and security groups is incorrect?

• A. Network ACLs protect subnets.
• B. Security groups protect Elastic Cloud Servers (ECSs).
• C. Users can configure security groups and network ACLs to increase the security of ECSs in their VPC.
• D. Both security groups and network ACLs support the allow and deny rules.

Which of the following statements about security groups is incorrect?

• A. After a user creates a security group, the user can add rules for the security group, and the rules will apply to any ECS in that group.
• B. The source and destination of a security group rule can only be IP addresses and cannot be security groups.
• C. A security group provides access control for Elastic Cloud Servers (ECSs) that have the same security protection requirements within a given Virtual Private Cloud (VPC).
• D. The system creates a security group for each user by default. The default security group rules allow all outgoing data packets and deny all incoming data packets.

Which of the following operations can be performed on Relational Database Service (RDS) instances?

• A. Scaling up storage space
• B. Changing the failover priority
• C. Rebooting a DB instance
• D. Deleting a DB instance

IAM users created by an administrator do not have default permissions. Which of the following statements about permissions is incorrect?

• A. IAM users can perform operations on cloud services as specified by the assigned permissions.
• B. FullAccess permissions provide read-only access to all services except IAM.
• C. Permissions are classified into roles and policies based on granularity.
• D. To assign permissions to new users, add them to one or more groups, then attach permissions policies or roles to these groups. The users inherit permissions from their groups.

How does Cloud Trace Service (CTS) notify subscribed users when key operations occur?

• A. WeChat
• B. SMS
• C. Email
• D. Phone call