Which of the following systems would not respond correctly to an nmap XMAS scan?

A.
Windows 2000 Server running IIS 5

B.
Any Solaris version running SAMBA Server

C.
Any version of IRIX

D.
RedHat Linux 8.0 running Apache Web Server

Explanation:
When running a XMAS Scan, if a RST packet is received, the port is considered closed, while no response means it is open|filtered. The big downside is that not all systems follow RFC 793 to the letter. A number of systems send RST responses to the probes regardless of whether the port is open or not. This causes all of the ports to be labeled closed. Major operating systems that do this are Microsoft Windows, many Cisco devices, BSDI, and IBM OS/400.