Andrew is an Ethical Hacker who was assigned the task of discovering all the active devices hidden by a restrictive firewall in the IPv4 range in a given target network. Which of the following host di

UDP scan is a port-scanning technique used to identify open UDP services on already-known hosts, not a host discovery method capable of bypassing firewall filtering.

TCP Maimon scan sends FIN/ACK probes to infer port state on known hosts and is a port scanning technique, not a host discovery method designed to circumvent firewalls.

ARP ping scan ('app ping scan' is likely a typographical rendering of 'arp ping scan') sends ARP requests at OSI Layer 2, which bypasses firewall rules that operate at Layer 3 and above. Because ARP is fundamental to IP communication on local networks, it is almost never filtered, allowing discovery of hosts that block ICMP or TCP-based probes. Nmap implements this via the -PR flag and uses it automatically when scanning local subnets.

ACK flag probe scan is used to map firewall rulesets and distinguish filtered from unfiltered ports, not to discover which hosts are active in a network range.