Which one of the following describes a bastion host?

A.
A physically shielded computer located in a data center or vault.

B.
A computer which maintains important data about the network.

C.
A computer which plays a critical role in a firewall configuration.

D.
A computer used to monitor the vulnerability of a network.

Explanation:
A bastion host or screened host is just a firewall system logically positioned between
a private network and an untrusted network. – Ed Tittle CISSP Study Guide (sybex) pg 93