How does an EC$2$ security group contribute to the overall security of EC$2$ instances?

By automating the scaling of instances to ensure optimal performance and resource utilization.

By monitoring and logging activities within instances for auditing and analysis purposes.

By controlling inbound and outbound traffic, serving as a virtual firewall for enhanced security.

By facilitating the streamlined deployment of software packages and updates to instances.

By managing and allocating storage resources based on user$-$defined quotas.