Which action would provide the minimum security requirements for a small office network?

• A. Implementing a firewall
• B. Installing a wireless network
• C. Installing antivirus software
• D. Implementing an intrusion detection system

Answer: (A)

Having a firewall at the network boundary establishes the basic security boundary and controls what traffic is allowed to enter or leave the small office network. By filtering packets based on rules, a firewall blocks unwanted access from the internet while permitting legitimate communication, reducing exposure to external threats and limiting what can reach internal devices. This is the fundamental step in securing a small office network because it enforces a defined policy for inbound and outbound traffic and can provide basic protections like NAT to hide internal addresses.

While antivirus software protects individual devices, and an intrusion detection system monitors for suspicious activity, they address different layers and needs. Antivirus helps hosts stay clean after threats arrive, but it doesn’t prevent unauthorized network access or control traffic between networks. An intrusion detection system highlights problems but doesn’t by itself block traffic unless paired with other controls. A wireless network, if not secured and managed, can introduce risks; it’s a connectivity feature, not a protective measure, and it relies on other controls to enforce security.

So, implementing a firewall provides the essential perimeter defense required for a small office, making it the most appropriate choice for minimum security requirements.