It is a data integrity assurance software aimed at detecting and reporting
accidental or malicious changes to data.
The following answers are incorrect :
Nessus is incorrect as it is a vulnerability scanner used by hackers in discovering
vulnerabilities in a system.
Saint is also incorrect as it is also a network vulnerability scanner likely to be used by
hackers.
Nmap is also incorrect as it is a port scanner for network exploration and likely to be used
by hackers.
Reference :
Tripwire : http://www.tripwire.com
Nessus : http://www.nessus.org
Saint : http://www.saintcorporation.com/saint
Nmap : http://insecure.org/nmap

Section: Access Control
Explanation/Reference:
Access controls are meant to protect facilities and computers as well as people.
In some situations, the objectives of physical access controls and the protection of people's lives may come into conflict. In theses situations, a person's life always takes precedence.
Many physical security controls make entry into and out of a facility hard, if not impossible. However, special consideration needs to be taken when this could affect lives. In an information processing facility, different types of locks can be used and piggybacking should be prevented, but the issue here with automatic locks is that they can either be configured as fail-safe or fail-secure.
Since there should only be one access door to an information processing facility, the automatic lock to the only door to a man-operated room must be configured to allow people out in case of emergency, hence to be fail- safe (sometimes called fail-open), meaning that upon fire alarm activation or electric power failure, the locking device unlocks. This is because the solenoid that maintains power to the lock to keep it in a locked state fails and thus opens or unlocks the electronic lock.
Fail Secure works just the other way. The lock device is in a locked or secure state with no power applied.
Upon authorized entry, a solinoid unlocks the lock temporarily. Thus in a Fail Secure lock, loss of power of fire alarm activation causes the lock to remain in a secure mode.
Reference(s) used for this question:
Harris, Shon (2012-10-18). CISSP All-in-One Exam Guide, 6th Edition (p. 451). McGraw-Hill. Kindle Edition.
and
Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 20249-20251). Auerbach Publications. Kindle Edition.

They are responsible for security of the organization and the protection of its assets.
The following answers are incorrect because :
Data owner is incorrect as data owners should not decide as to what security measures should be applied.
Auditor is also incorrect as auditor cannot decide as to what security measures should be applied.
The information security specialist is also incorrect as they may have the technical knowledge of how security measures should be implemented and configured , but they
should not be in a position of deciding what measures should be applied.
Reference : Shon Harris AIO v3 , Chapter-3: Security Management Practices , Page : 51.

Explanation/Reference:
The first types of firewalls were packet filtering firewalls. It is the most basic firewall making access decisions based on ACL's. It will filter traffic based on source IP and port as well as destination IP and port. It does not understand the context of the communication and inspects every single packet one by one without understanding the context of the connection.
"Second generation firewall" is incorrect. The second generation of firewall were Proxy based firewalls.
Under proxy based firewall you have Application Level Proxy and also the Circuit-level proxy firewall. The application level proxy is very smart and understand the inner structure of the protocol itself. The Circui- Level Proxy is a generic proxy that allow you to proxy protocols for which you do not have an Application Level Proxy. This is better than allowing a direct connection to the net. Today a great example of this would be the SOCKS protocol.
"Third generation firewall" is incorrect. The third generation firewall is the Stateful Inspection firewall. This type of firewall makes use of a state table to maintain the context of connections being established.
"Fourth generation firewall" is incorrect. The fourth generation firewall is the dynamic packet filtering firewall.
References:
CBK, p. 464
AIO3, pp. 482 - 484
Neither CBK or AIO3 use the generation terminology for firewall types but you will encounter it frequently as a practicing security professional. See http://www.cisco.com/univercd/cc/td/doc/product/iaabu/centri4/ user/scf4ch3.htm for a general discussion of the different generations.

Explanation/Reference:
Steganography is a secret communication where the very existence of the message is hidden. For example, in a digital image, the least significant bit of each word can be used to comprise a message without causing any significant change in the image. Key clustering is a situation in which a plaintext message generates identical ciphertext messages using the same transformation algorithm but with different keys. Cryptology encompasses cryptography and cryptanalysis. The Vernam Cipher, also called a one-time pad, is an encryption scheme using a random key of the same size as the message and is used only once. It is said to be unbreakable, even with infinite resources.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 4: Cryptography (page 134).