What tool do you use to determine whether a host is vulnerable to known attacks?

What tool do you use to determine whether a host is vulnerable to known attacks?

A.
Padded Cells

B.
Vulnerability analysis

C.
Honey Pots

D.
IDS

Explanation:
Vulnerability analysis (also known as vulnerability assessment) tools test to determine
whether a network or host is vulnerable to known attacks. Vulnerability assessment
represents a special case of the intrusion detection process. The information sources
used are system state attributes and outcomes of attempted attacks. The information
sources are collected by a part of the assessment engine. The timing of analysis is
interval-based or batch-mode, and the type of analysis is misuse detection. This means
that vulnerability assessment systems are essentially batch mode misuse detectors that
operate on system state information and results of specified test routines.