John works as a professional Ethical Hacker.

NetBIOS is a Microsoft service that enables applications on different computers to communicate within a LAN. NetBIOS systems identify themselves with a 15-character unique name and use Server Message Block, which allows Remote directory, file and printer sharing, etc. The default port value of NetBIOS Name Resolution Service is 137/UDP. Answer: A is incorrect. Hypertext Transfer Protocol (HTTP) is a client/server TCP/IP protocol used on the World Wide Web (WWW) to display Hypertext Markup Language (HTML) pages. HTTP defines how messages are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands. For example, when a client application or browser sends a request to the server using HTTP commands, the server responds with a message containing the protocol version, success or failure code, server information, and body content, depending on the request. HTTP uses TCP port 80 as the default port. Answer: D is incorrect. The default port of HTTPS is TCP/443. Hypertext Transfer Protocol Secure (HTTPS) protocol is a protocol used in the Universal Resource Locater (URL) address line to connect to a secure site. If a site has been made secure by using the Secure Sockets Layer (SSL) then HTTPS, instead of HTTP protocol, should be used as a protocol type in the URL. Answer: B is incorrect. TELNET is a command-line connectivity tool that starts terminal emulation with a remote host running the telnet server service. TELNET allows users to communicate with a remote computer, offers the ability to run programs remotely, and facilitates remote administration. The TELNET utility uses the Telnet protocol for connecting to a remote computer running the Telnet server software, to access files. It uses TCP port 23 by default.