Answer CLIPPER refers to the US government Escrowed Encryption Standard. Answer ECHELON refers to the large-scale monitoring of RF transmissions. Answer ECHO is a distracter.

The correct answer is Relation. The fundamental entity in a relational database is the relation in the form of a table. Answer Domain is the set of allowable attribute values, and answers Pointer and Cost are distracters.

Source: Veritas eLearning CD - Introducing Disaster Recovery Planning, Chapter 1.
All of the others can be replaced or repaired. Data that is lost and was not backed up, cannot be
restored.

The correct answer is "Acquires data to establish a normal system operating profile". A statistical anomaly-based intrusion detection system acquires data to establish a normal system operating profile.
Answer "Refers to a database of known attack signatures" is incorrect because it is used in signature-based intrusion detection. Answer "Will detect an attack that does not significantly change the system's operating characteristics." is incorrect because a statistical anomaly-based intrusion detection system will not detect an attack that does not significantly change the system operating characteristics. Similarly, answer "Does not report an event that caused a momentary anomaly in the system." is incorrect because the statistical anomaly-based IDS is susceptible to reporting an event that caused a momentary anomaly in the system.