Why would an attacker want to perform a scan on port 137?

Why would an attacker want to perform a scan on port 137?

A.
To discover proxy servers on a network

B.
To disrupt the NetBIOS SMB service on the target host

C.
To check for file and print sharing on Windows systems

D.
To discover information about a target host using NBTSTAT

Explanation:
Microsoft encapsulates netbios information withinTCP/Ip using ports 135-139.It is
trivial for an attacker to issue thefollowing command:
nbtstat -A (your Ip address)
Fromtheir windows machine and collect information about your windowsmachine (if you are not
blocking traffic to port 137 at your borders).