A dry pipe system is used in areas where the water in the pipes is subject to freezing, and to minimize the chances of accidental discharge of water if the pipes would freeze in the winter time, and It minimizes chances of accidental discharge of water as well by not releasing the water until the pressure in the pipe would drop due to one of the sprinkler head being opened.
A Dry Pipe system has the water being held back from charging the sprinkler pipe system by a special kind of check valve called a "dry pipe valve" or "clapper valve". A dry pipe system is also a system which the pipes are filled with pressurized air or nitrogen rather than water. The air uses a mechanical advantage which holds back a device known as a dry pipe valve or clapper valve that prevent the water from getting into the pipe when it is pressurized. A small amount of water, called priming water, is also inside the dry pipe system, which is filled with either air or nitrogen under pressure.
The sprinkler pipe system is filled with pressurized air or nitrogen, which keeps the dry pipe valve closed using mechanical advantage. When any of the sprinkler valves open, the pressurized air or nitrogen is released, and the dropping pressure permits the dry pipe valve to open. It's primary use is to protect the sprinkler pipes from freezing.
A Wet Pipe system has the pipes always charged with water, and the thermal-fusible link in each sprinkler head is holding back the water. If any sprinkler head is exposed to enough heat, for long enough, the link will break/melt and water will be discharged. A wet pipe system is generally used when there is no danger of the water in the pipes freezing or when there are no special conditions that require a special purpose sprinkler system.
A Preaction Pipe system is used where accidental activation is undesired. It is similar to a Dry Pipe system, except one or more other interlocks, such as fire/heat sensors, are used in addition to sprinkler head opening and relieving the air pressure, which then permits the water to charge the sprinkler pipe system and flow through the open sprinkler head. This system has the added value of requiring a series of events before the water is actually permitted to flow, which can enable personnel to handle a small fire or incident without the flow of water.
All of the other answers were NOT true so they were wrong choices
The following reference(s) were/was used to create this question: Shon Harris, AIO v5, pg 444-445 and Ronald Krutz adn Russell Vines, The CISSP and CAP Prep Guide, pg 530

An audit is an independent and objective examination of an organization's activities, systems, processes, or controls to evaluate their adequacy, effectiveness, efficiency, and compliance with applicable standards, policies, laws, or regulations. An audit plan is a document that outlines the objectives, scope, methodology, criteria, schedule, and resources of an audit. The most crucial element of a successful audit plan is defining the scope of the audit to be performed, which is the extent and boundaries of the audit, such as the subject matter, the time period, the locations, the departments, the functions, the systems, or the processes to be audited. The scope of the audit determines what will be included or excluded from the audit, and it helps to ensure that the audit objectives are met and the audit resources are used efficiently and effectively. Identifying the security controls to be implemented, working with the system owner on new controls, and acquiring evidence of systems that are not compliant are all important tasks in an audit, but they are not the most crucial for a successful audit plan, as they depend on the scope of the audit to be defined first. References: CISSP All-in-One Exam Guide, Eighth Edition, Chapter 1, Security and Risk Management, page 54. Official (ISC)2 CISSP CBK Reference, Fifth Edition, Chapter 1, Security and Risk Management, page 69.

In the Clark-Wilson model, the subject no longer has direct access to objects but instead must access them through programs (well -formed transactions). The Clark-Wilson integrity model provides a foundation for specifying and analyzing an integrity policy for a computing system. The model is primarily concerned with formalizing the notion of information integrity. Information integrity is maintained by preventing corruption of data items in a system due to either error or malicious intent. An integrity policy describes how the data items in the system should be kept valid from one state of the system to the next and specifies the capabilities of various principals in the system. The model defines enforcement rules and certification rules.
Clark-Wilson is more clearly applicable to business and industry processes in which the integrity
of the information content is paramount at any level of classification.
Integrity goals of Clark-Wilson model:
Prevent unauthorized users from making modification (Only this one is addressed by the Biba
model).
Separation of duties prevents authorized users from making improper modifications.
Well formed transactions: maintain internal and external consistency i.e. it is a series of operations
that are carried out to transfer the data from one consistent state to the other.
The following are incorrect answers:
The Biba model is incorrect. The Biba model is concerned with integrity and controls access to
objects based on a comparison of the security level of the subject to that of the object.
The Bell-LaPdaula model is incorrect. The Bell-LaPaula model is concerned with confidentiality
and controls access to objects based on a comparison of the clearence level of the subject to the
classification level of the object.
The information flow model is incorrect. The information flow model uses a lattice where objects
are labelled with security classes and information can flow either upward or at the same level. It is
similar in framework to the Bell-LaPadula model.
References:
ISC2 Official Study Guide, Pages 325 - 327
AIO3, pp. 284 - 287
AIOv4 Security Architecture and Design (pages 338 - 342)
AIOv5 Security Architecture and Design (pages 341 - 344)
Wikipedia at: https://en.wikipedia.org/wiki/Clark-Wilson_model