To assign a new policy to a compliance standard in Prisma Cloud, the administrator needs to edit the policy and navigate to the step where compliance standards are managed. By clicking the '+' button, the administrator can add the policy to a specific compliance standard, provide necessary details, and confirm the assignment. This integrates the custom policy into the chosen compliance standard, ensuring that compliance checks include the newly defined policy criteria.

The RQL provided is designed to capture certain network-related operations, including the creation and deletion of compute firewall rules. The audit event snippet that matches this RQL is Option D, as it includes a "compute.firewalls.delete" operation within its request, aligning with the specified RQL's criteria.