The Answer: Power line conditioning is a protective measure against noise. It helps to ensure the transmission of clean power.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the
Ten Domains of Computer Security, page 334.

Section: Software Development Security

Explanation/Reference:
Explanation:
A Type II error, or false acceptance rate, is when the system accepts impostors who should be rejected.
Incorrect Answers:
A: A Type I error, or false rejection rate, is when a biometric system rejects an authorized individual.
C: A Type III error does not exist in biometrics.
D: The crossover error rate (CER) is a percentage that signifies the point at which the false rejection rate equals the false acceptance rate.
References:
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, 2013, pp. 188
http://www.technovelgy.com/ct/Technology-Article.asp?ArtNum=93

Digital Signal level 1 (DS-1) is the framing specification used for transmitting digital signals at 1.544 Mbps on a T1 facility. DS-0 is the framing specification used in transmitting digital signals over a single 64 Kbps channel over a T1 facility. DS-3 is the framing specification used for transmitting digital signals at 44.736 Mbps on a T3 facility. DS-2 is not a defined framing specification.
Source: 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 114).