This example of a script injection attack would be best mitigated by input sanitization. Input sanitization involves cleaning or filtering user inputs to ensure that they do not contain harmfuldata, such as malicious scripts. This prevents attackers from executing script-based attacks (e.g., Cross-Site Scripting or XSS).
Nmap command is unrelated to input sanitization, as it is a network scanning tool.
Email phishing attempts require different mitigations, such as user training.
Browser warnings about insecure connections involve encryption protocols, not input validation