Which of the following tools uses exploits to break into remote operating systems?

Nmap is a network discovery and port scanning tool used to identify hosts and open services, not to exploit them.

John the Ripper is a password cracking tool that attacks password hashes offline and does not interact with remote operating systems.

The Metasploit Framework is a penetration testing platform containing a library of known exploits and payloads specifically designed to compromise remote operating systems. An attacker or tester selects an exploit module, configures the target, and delivers a payload to gain unauthorized access or control. This active exploitation capability is what distinguishes Metasploit from reconnaissance or assessment tools.

Nessus is a vulnerability scanner that identifies weaknesses in systems but does not actively exploit them to gain access.