Which of the following is a primary function of a firewall?

The primary function of a firewall is to monitor network traffic. Firewalls serve as a barrier between a trusted internal network and untrusted external networks, such as the internet. They analyze incoming and outgoing traffic and enforce pre-defined security rules to determine which traffic should be allowed or blocked. This vital role helps prevent unauthorized access to or from a private network and protects against various cyber threats, making it an essential component of network security.

In contrast to monitoring network traffic, other options do not align with a firewall's primary function. Storing data pertains more to data storage systems rather than the traffic management role of a firewall. Encrypting files is a security measure that secures data, but it is typically handled by encryption software rather than a firewall. Customer support is a service function unrelated to the security features of firewalls. Therefore, monitoring network traffic effectively captures the core purpose of a firewall in the realm of cybersecurity.