A jump box is a hardened system that provides secure access to isolated or sensitive devices on a separate network. Breakdown of Options: A: Jump box - # Correct answer. Acts as a middle point for secure remote access. B: API gateway - Used for managing API calls, not remote access to isolated devices. C: Secure Shell (SSH) - Requires direct connectivity, which may not be available for an isolated device. D: Clientless VPN - Allows web-based VPN access, but does not guarantee access to isolated devices. Reference: CompTIA Network+ (N10-009) Official Study Guide - Domain 3.4: Implement secure remote access methods.