Which of the following solutions provides the most flexibility when testing new security controls prior to
implementation?

A.
Trusted OS

B.
Host software baselining

C.
OS hardening

D.
Virtualization

Explanation:
Virtualization is used to host one or more operating systems in the memory of a single host computer and
allows multiple operating systems to run simultaneously on the same hardware. Virtualization offers the
flexibility of quickly and easily making backups of entire virtual systems, and quickly recovering the virtual
system when errors occur. Furthermore, malicious code compromises of virtual systems rarely affect the host
system, which allows for safer testing and experimentation.