Which of the following technologies can be used as a means to isolate a host OS from some types of security threats？（）

A.A static NAT uses a one to many mapping.
B.A static NAT uses a many to one mapping.
C.A static NAT uses a many to many mapping.
D.A static NAT uses a one to one mapping.

A.S/MIME
B.SSH
C.3DES
D.IPSec

A.Vulnerability assessment
B.Imaging software
C.Patch management
D.Configuration baseline