An automatic fire alarm system is designed for detecting the unwanted presence of fire by monitoring environmental changes associated with combustion. In general, a fire alarm system is classified as either automatically actuated, manually actuated, or both. Automatic fire alarm systems are intended to notify the building occupants to evacuate in the event of a fire or other emergency, to report the event to an off-premises location in order to summon emergency services, and to prepare the structure and associated systems to control the spread of fire and smoke. Answer option C is incorrect. A fire suppression system is used in conjunction with smoke detectors and fire alarm systems to improve and increase public safety. Answer option A is incorrect. Gaseous fire suppression is a term to describe the use of inert gases and chemical agents to extinguish a fire. Answer option B is incorrect. A fire sprinkler is the part of a fire sprinkler system that discharges water when the effects of a fire have been detected, such as when a predetermined temperature has been reached.

A stateful firewall is a firewall that keeps track of the state of network connections (such as TCP streams, UDP communication) traveling across it. The firewall is programmed to distinguish legitimate packets for different types of connections. Only packets matching a known connection state will be allowed by the firewall; others will be rejected. Answer option B is incorrect. A stateless packet filter firewall allows direct connections from the external network to hosts on the internal network and is included with router configuration software or with Open Source operating systems.
Answer option C is incorrect. It applies security mechanisms when a TCP or UDP connection is established.
Answer option D is incorrect. An application gateway firewall applies security mechanisms to specific applications, such as FTP and Telnet servers.

demilitarized zone
Explanation:
A demilitarized zone (DMZ) is a physical or logical subnetwork that contains and exposes external services of
an organization to a larger network, usually the Internet. The purpose of a DMZ is to add an additional layer of
security to an organization's Local Area Network (LAN); an external attacker only has access to equipment in
the DMZ, rather than the whole of the network. Hosts in the DMZ have limited connectivity to specific hosts in
the internal network, though communication with other hosts in the DMZ and to the external network is allowed.
This allows hosts in the DMZ to provide services to both the internal and external networks, while an
intervening firewall controls the traffic between the DMZ servers and the internal network clients. In a DMZ
configuration, most computers on the LAN run behind a firewall connected to a public network such as the
Internet.

A global area network (GAN) is a network that is used for supporting mobile communications across an arbitrary number of wireless LANs, satellite coverage areas, etc. The key challenge in mobile communications is handing off the user communications from one local coverage area to the next.
Answer option B is incorrect. A wide area network (WAN) is a geographically dispersed telecommunications network. The term distinguishes a broader telecommunication structure from a local area network (LAN). A wide area network may be privately owned or rented, but the term usually connotes the inclusion of public (shared user) networks. An intermediate form of network in terms of geography is a metropolitan area network (MAN). A wide area network is also defined as a network of networks, as it interconnects LANs over a wide geographical area.
Answer option D is incorrect. A home area network (HAN) is a residential LAN that is used for communication between digital devices typically deployed in the home, usually a small number of personal computers and accessories, such as printers and mobile computing devices.
Answer option A is incorrect. The Local Area Network (LAN) is a group of computers connected within a restricted geographic area, such as residence, educational institute, research lab, and various other organizations. It allows the users to share files and services, and is commonly used for intra-office communication. The LAN has connections with other LANs via leased lines, leased services, or by tunneling across the Internet using the virtual private network technologies.