Refer to the exhibit.

Based on the exhibit and the OT Security 7.6 Architect standards for Secure Remote Access :

Secure Tunneling (Statement A) : The exhibit shows a Remote PC connecting through a VPN Cloud to the Edge-FortiGate . In the Fortinet architecture, IPsec VPN is the primary method for establishing a secure, encrypted tunnel for remote administrators or supervisors to access the internal OT segments (Level 2/3) from an external location.

Multi-Factor Authentication (Statement B) : Secure remote access in OT environments (aligned with IEC 62443 standards) requires strong authentication. The study guide emphasizes the use of FortiToken to provide Two-Factor Authentication (2FA) for VPN users, ensuring that compromised credentials alone are not enough to gain access to critical infrastructure.

FSSO (Statement D) : Fortinet Single Sign-On is generally used for identifying internal users already on the network to apply identity-based policies; it is not the primary mechanism for establishing the remote connection itself.

SD-WAN (Statement C) : While SD-WAN can manage the path of the VPN traffic, it is a WAN optimization and reliability feature, not a "secure remote access" feature for a supervisor in the context of authentication and encryption.