It provides secure, remote logon and other secure client/server facilities.

The correct answer is SSH (Secure Shell). SSH provides a secure, encrypted channel for remote logon and other client/server services over an insecure network. It replaces older protocols like Telnet, which transmit data in plaintext and are vulnerable to eavesdropping. SSH ensures confidentiality and integrity through strong encryption, making it ideal for secure remote administration.\nIPSec operates at the network layer to secure IP communications but is not primarily designed for remote logon sessions. HTTPS secures web traffic between browsers and servers, focusing on HTTP protocol protection rather than general remote shell access. SLP (Service Location Protocol) is used for discovering network services and does not provide security or remote access capabilities. Therefore, SSH is the only protocol listed that specifically offers secure remote logon and client/server facilities.