What can you conclude from the following nmap results?

What can you conclude from the following nmap results?

Starting nmap V. 3.10ALPHA9 ( www.insecure.org/nmap/ )
Interesting ports on 192.168.1.1:

(The 1592 ports scanned but not shown below are in state: closed)

PortStateService
21/tcpopenftp
25/tcpopensmtp
80/tcpopenhttp
389/tcpopenldap
443/tcpopenhttps
3268/tcpopengc

Remote operating system guess: Too many signatures match to reliably guess the OS. Nmap run completed — 1 IP address (1 host up) scanned in 91.66 seconds

A.
The system is not running Linux or Solaris

B.
The system is not firewall enabled

C.
The system is a Windows Domain Controller

D.
The system is not properly patched

Explanation:
There is no reports of any ports being filtered.