Choice "B" is correct. In a denial of service attack, one computer bombards another computer with a flood of information intended to keep legitimate users from accessing the target computer or network. A sudden surge of false requests that cause a company's server to crash is a denial of service attack.Choice "a" is incorrect. A spoofing attack is a breach of network security resulting from a person or program successfully impersonating a legitimate network user for illegitimate purposes.Choice "d" is incorrect. Piggybacking is the practice of using another person or organization's wireless network connection without the express permission of the subscriber or owner of the network.Choice "c" is incorrect. An eavesdropping attack seeks to access a network and steal or eavesdrop on communications in an attempt to illicitly obtain passwords or other confidential or sensitive information.