Hardware and software placed between an organization's internal network and an external network to prevent outsiders from invading private networks best describes a(n) ______________.

Answer: Option B

Hardware and software placed between an organization's internal network and an external network to prevent outsiders from invading private networks best describes a Firewall. A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. A firewall typically establishes a barrier between a trusted internal network and untrusted external network, such as the Internet.