Which security measure can help defend against unauthorized access?

Configuring firewalls is a crucial security measure that helps defend against unauthorized access by controlling the incoming and outgoing network traffic based on predetermined security rules. Firewalls serve as a barrier between a trusted internal network and untrusted external networks, such as the internet. By analyzing data packets, they can block or allow traffic based on specific criteria, thereby preventing unauthorized users from accessing sensitive systems and data.

A properly configured firewall can help protect against various security threats, including unauthorized access attempts, data breaches, and the spread of malware. This defensive layer, often combined with additional security measures like intrusion detection systems and strict access controls, significantly enhances an organization's overall security posture. In contrast, using shared accounts, enabling guest access, or displaying passwords openly could lead to increased vulnerability and potential unauthorized access, making them inadequate choices in comparison to firewall configuration.