Which statement about security groups in Huawei FusionCompute is incorrect?

The selected statement is that a virtual machine can communicate with the outside world only after a security group is created and rules are added. This statement is incorrect because, while security groups play a vital role in managing network access and policies, they are not the sole determining factor for a virtual machine's ability to communicate with external networks.

In many cloud environments, including Huawei FusionCompute, virtual machines can have default network settings that allow outbound traffic even before any explicit security group is defined. Moreover, the communication can also depend on underlying network configurations, such as firewalls, routing, and other network settings. Therefore, it is possible for a virtual machine to communicate with the outside world without the necessity of having a security group explicitly set up first.

The other statements about security groups are indeed correct. For instance, they properly describe how security groups can be assigned to multiple network cards on a virtual machine, the shared use of security group rules among NICs in the same group, and that a security group fundamentally consists of collection rules for access control. Each of these points accurately reflects the functionality of security groups in Huawei FusionCompute, reinforcing the critical understanding of how they operate within the cloud infrastructure.