Concept:A security risk is any malicious activity or threat that can harm a computer system or data. A firewall is a protective tool, not a threat.Explanation:Hacking means unauthorized access to a system. Phishing tricks users into giving sensitive information. Pharming redirects website traffic to fake sites. All three are security risks. A firewall monitors and controls network traffic based on set rules. It creates a barrier between a trusted network and untrusted networks. A firewall is a security measure, not a risk. Hence, among the given options, firewall is the only one that is not a security risk.Answer:B. Firewall