A. Deploy self-signed certificates at each site to simplify local certificate validation and reduce dependencies on a centralized CA. Turn off certificate revocation checks for lower overhead, rely on IP-based rules for GlobalProtect authentication, and use a single certificate profile for both users and devices.

B. Distribute the root and intermediate CA certificates via Panorama as shared objects to ensure all firewalls have a consistent trust chain. Configure OCSP responder profiles on each firewall to offload revocation checks to an internal OCSP server while keeping CRL checks as a fallback. Maintain separate certificate profiles for user and device authentication and use an automated enrollment method - such as Group Policy or SCEP - to deploy certificates to endpoints.

C. Configure each firewall independently to trust the root and intermediate CA certificates. Rely only on manual CRL checks for certificate revocation, and import both user and device certificates directly into each firewall's local certificate store for authentication.

D. Obtain wildcard certificates from a public CA for both user and device authentication, and configure firewalls to perform CRL polling at the default update interval. Manually install user certificates on endpoints and synchronize firewall certificate stores through frequent manual SSH updates to maintain consistency.