What is the maximum number of source tags that can be used in a single firewall rule?

The correct response is based on the limitation established by Google Cloud's networking features, specifically the number of source tags that can be applied in a single firewall rule. In Google Cloud, a firewall rule can utilize a maximum of 30 source tags. This limit allows for effective organization and management of security policies, ensuring that these rules can still accommodate a substantial yet manageable number of sources.

Within the context of cloud security, source tags are used to identify instances that the firewall rule will apply to. By allowing up to 30 source tags, Google Cloud provides flexibility for administrators to group and segment instances based on specific applications, departments, or roles, while also maintaining a clear structure that facilitates the monitoring and enforcement of network security policies.

While the other options suggest higher limits, they exceed the established limit of 30, which the platform explicitly outlines in its documentation regarding firewall rules. Hence, the choice of 30 reflects both practical applicability in real-world configurations and adherence to Google Cloud standards.