<P> Physical security describes security measures that are designed to deny unauthorized access to facilities, equipment and resources and to protect personnel and property from damage or harm (such as espionage, theft, or terrorist attacks). Physical security involves the use of multiple layers of interdependent systems which include CCTV surveillance, security guards, protective barriers, locks, access control protocols, and many other techniques . </P> <P> Physical security systems for protected facilities are generally intended to: </P> <Ul> <Li> deter potential intruders (e.g. warning signs and perimeter markings); </Li> <Li> detect intrusions and monitor / record intruders (e.g. intruder alarms and CCTV systems); and </Li> <Li> trigger appropriate incident responses (e.g. by security guards and police). </Li> </Ul> <Li> deter potential intruders (e.g. warning signs and perimeter markings); </Li>

Which of the following should be considered as delaying devices in physical security