Section: Network and Telecommunications
Explanation/Reference:
Some sites choose not to implement Trivial File Transfer Protocol (TFTP) due to the inherent security risks.
TFTP is a UDP-based file transfer program that provides no security. There is no user authentication.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 88.

Explanation/Reference:
The other answers are not correct because:
You are always looking for the "best" answer. While each of the answers listed here could be considered correct in that each of them require input from the security staff, the best answer is for that input to happen at all phases of the project.
Reference:
Official ISC2 Guide page: 556
All in One Third Edition page: 832 - 833

A weakness of the signature-based (or knowledge-based) intrusion detection approach is that only attack signatures that are stored in a database are detected. Network-based intrusion detection can either be signature-based or statistical anomaly-
based (also called behavior-based).
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the
Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 2: Access control
systems (page 49).

Source: TIPTON, Hal, (ISC)2, Introduction to the CISSP Exam presentation.

Section: Network and Telecommunications
Explanation/Reference:
This layer of the DoD Model is also sometimes called Transport in some books but the proper name is Host-to- Host as per the RFC document.
The host-to-host layer provides for reliable end-to-end communications, ensures the data's error-free delivery, handles the data's packet sequencing, and maintains the data's integrity.
It is comparable to the transport layer of the OSI model.
Reference(s) used for this question:
http://en.wikipedia.org/wiki/Internet_protocol_suite
and
http://technet.microsoft.com/en-us/library/cc786900%28v=ws.10%29.aspx
and
KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 85).