Which of the following best describes footprinting?

A$.$ A design in which a network maintains two connections to its ISP

B$.$ The process of determining the operating system and version of a network node

C$.$ A server deliberately set up as insecure in an effort to trap or track attackers

D$.$ A network mechanism that adds a simple label to each network packet, making routing of the packet faster than routing based on data in the header portion of the packet