Source: The CISSP Examination Textbook- Volume 2: Practice by S. Rao Vallabhaneni.

Explanation/Reference:
When using packet switching, messages are broken down into packets. Source and destination address are added to each packet so that when passing through a network node, they can be examined and eventually rerouted through different paths as conditions change. All message packets may travel different paths and not arrive in the same order as sent. Packets need to be collected and reassembled into the original message at destination.
Source: TIPTON, Hal, (ISC)2, Introduction to the CISSP Exam presentation.

Section: Cryptography
Explanation/Reference:
A One-Time Pad uses a keystream string of bits that is generated completely at random that is used only once.
Because it is used only once it is considered unbreakable.
The following answers are incorrect:
Symmetric ciphers. This is incorrect because a Symmetric Cipher is created by substitution and transposition.
They can and have been broken
DES codebooks. This is incorrect because Data Encryption Standard (DES) has been broken, it was replaced by Advanced Encryption Standard (AES).
Elliptic Curve Cryptography. This is incorrect because Elliptic Curve Cryptography or ECC is typically used on wireless devices such as cellular phones that have small processors. Because of the lack of processing power the keys used at often small. The smaller the key, the easier it is considered to be breakable. Also, the technology has not been around long enough or tested thourough enough to be considered truly unbreakable.

Hiding

Physical security and environmental security are part of operational controls, and are measures taken to protect systems, buildings, and related supporting infrastructures against threats associated with their physical environment. All the questions above are useful in assessing physical access controls except for the one regarding operating system configuration, which is a logical access control. Source: SWANSON, Marianne, NIST Special Publication 800-26, Security Self-Assessment Guide for Information Technology Systems, November 2001 (Pages A-21 to A-24).