Fortinet ' s unified SASE architecture supports multiple methods of securing private application access, including identity-based Zero Trust Network Access and connectivity through Secure SD-WAN.

Option B is correct because ZTNA provides an application-centric alternative to traditional remote-access VPN architectures. Instead of providing broad network connectivity, ZTNA authenticates users, evaluates device security posture, and grants access only to explicitly authorized applications.

Fortinet ZTNA integrates identity verification, endpoint posture assessment, and application-specific security policies to reduce implicit trust.

Option C is correct because Secure SD-WAN enables encrypted and centrally managed connectivity between enterprise locations, cloud environments, and private resources. When integrated with FortiSASE, existing SD-WAN hubs can provide secure private application access through cloud security points of presence.

Option A is incorrect in this scenario because SD-WAN Branch On-ramp is primarily an ingress method for connecting branch networks to FortiSASE. Although it can participate in a broader private-access architecture, it is not the general VPN-replacement technology being tested.

Option D is incorrect because SWG and CASB primarily address internet and SaaS application security rather than providing the private network connectivity and application-specific access control required here.

ZTNA delivers granular access enforcement, while Secure SD-WAN supplies resilient and secure enterprise connectivity.