The following concerns usually apply to what type of architecture?
Desktop systems can contain sensitive information that may be at
risk of being exposed.
Users may generally lack security awareness.
Modems present a vulnerability to dial-in attacks.
Lack of proper backup may exist.

A.
Centralized

B.
Open system

C.
Distributed

D.
Symmetric

Explanation:
Additional concerns associated with distributed systems include:
A desktop PC or workstation can provide an avenue of access
into critical information systems of an organization.
Downloading data from the Internet increases the risk of
infecting corporate systems with a malicious code or an
unintentional modification of the databases.
A desktop system and its associated disks may not be protected
from physical intrusion or theft.
* For answer centralized system all the characteristics cited do
not apply to a central host with no PCs or workstations with large
amounts of memory attached. Also, the vulnerability presented by a
modem attached to a PC or workstation would not exist.
* An open system or architecture is comprised of vendorindependent
subsystems that have published specifications and interfaces in order to permit operations with the
products of other suppliers. One advantage of an open system is that it is subject to review and
evaluation by independent parties.
* Answer Symmetric is a distracter.