What can he infer from this kind of response?

Blane is a network security analyst for his company. From an outside IP, Blane performs an XMAS scan using Nmap. Almost every port scanned does not illicit a response. What can he infer from this kind of response?

A.
These ports are open because they do not illicit a response.

B.
He can tell that these ports are in stealth mode.

C.
If a port does not respond to an XMAS scan using NMAP, that port is closed.

D.
The scan was not performed correctly using NMAP since all ports, no matter what their state, will illicit some sort of response from an XMAS scan.