Secure Access Service Edge combines enterprise network connectivity with cloud-delivered security services to provide consistent protection and optimized application access across distributed environments.

Option B is correct because Software-Defined WAN represents the networking component of SASE. It provides intelligent WAN connectivity, application-aware path selection, transport abstraction, and centralized traffic steering.

Security Service Edge, by contrast, focuses specifically on delivering security services from distributed cloud enforcement points. It does not inherently include the SD-WAN networking functions that form part of the broader SASE architecture.

Option A is incorrect because SWG is a core SSE capability that protects users against malicious websites, unwanted content, and web-based attacks.

Option C is incorrect because ZTNA is another fundamental SSE component. It implements explicit, identity-based access to authorized applications rather than granting unrestricted network connectivity.

Option D is incorrect because CASB provides visibility, governance, and security controls for cloud applications, making it part of SSE.

Fortinet implements the networking portion of unified SASE through FortiGate Secure SD-WAN and delivers SSE capabilities through FortiSASE.

Together, they provide secure internet access, secure private access, and secure SaaS access while maintaining consistent enterprise security policies across users and branch locations.