Which of the following scanning methods is most accurate and reliable, although it is easily detectable and hence avoided by a hacker?

TCP FIN scanning sends only a FIN packet to bypass firewalls for stealth, but it is unreliable because Windows systems respond identically to open and closed ports, producing inaccurate results.

TCP half-open (SYN) scanning intentionally avoids completing the handshake to reduce detectability, sacrificing the reliability and accuracy of a full connect scan.

TCP SYN/ACK scanning completes the full three-way handshake (SYN - SYN/ACK - ACK), ensuring accurate port state determination with no false positives. Because it establishes a real connection, it is logged by the target system and easily detected by firewalls and intrusion detection systems, which is why malicious actors avoid it in favor of stealthier techniques.

Xmas Tree scanning sets FIN, URG, and PSH flags simultaneously for stealth, but like FIN scanning it produces unreliable results across different OS implementations.