The correct answer is "To ensure that system changes are implemented in an orderly manner".
Answer "To guarantee that an operator is only given the privileges needed for the task" describes least privilege.
Answer "To guarantee that transaction records are retained IAW compliance requirements" describes record retention.
Answer "To assign parts of security-sensitive tasks to more than one individual" describes separation on duties.

The network layer contains the Internet Protocol (IP), the Internet Control Message
Protocol (ICMP), and the Internet Group Management Protocol (IGMP)
The following answers are incorrect:
Datagram Layer. Is incorrect as a distractor as there is no Datagram Layer.
Transport Layer. Is incorrect because it is used to data between applications and uses the TCP
and UDP protocols.
Data Link Layer. Is incorrect because this layer deals with addressing hardware.

The correct answer is "Legitimate users accessing networked services that would normally be restricted to them". Logon abuse entails an otherwise proper user attempting to access areas of the network that are deemed offlimits.
Answer "Breaking into a network primarily from an external source" is called network intrusion, and d refers to backdoor remote access.

Frame relay and X.25 are both examples of packet-switching technologies.
In packet-switched networks there are no dedicated connections between endpoints, and data is divided into packets and reassembled on the receiving end.
Frame Relay is an example of a packet-switched technology. Packet-switched networks enable end stations to dynamically share the network medium and the available bandwidth.
The following two techniques are used in packet-switching technology:
Variable-length packets
Statistical multiplexing
Variable-length packets are used for more efficient and flexible data transfers. These packets are switched between the various segments in the network until the destination is reached.
Statistical multiplexing techniques control network access in a packet-switched network.
The advantage of this technique is that it accommodates more flexibility and more efficient use of bandwidth. Most of today's popular LANs, such as Ethernet and Token Ring, are packet-switched networks.
Frame Relay often is described as a streamlined version of X.25, offering fewer of the robust capabilities, such as windowing and retransmission of last data that are offered in
X.25. This is because Frame Relay typically operates over WAN facilities that offer more reliable connection services and a higher degree of reliability than the facilities available during the late 1970s and early 1980s that served as the common platforms for X.25
WANs. As mentioned earlier, Frame Relay is strictly a Layer 2 protocol suite, whereas X.25 provides services at Layer 3 (the network layer) as well. This enables Frame Relay to offer higher performance and greater transmission efficiency than X.25, and makes Frame Relay suitable for current WAN applications, such as LAN interconnection.
The following answers are incorrect:
Circuit-switched services. An example of a circuit-switched service are Integrated Services
Digital Network (ISDN) and Point-to-Point Protocol (PPP). Frame Relay and X.25 do not use circuit switching technology.
Cell-switched services. This is a distractor.
Dedicated digital services. A packet switched network is commonly via a digital method, but is not dedicated. Examples of a Dedicated digital service might be a Permanent Virtual
Circuit (PVC), which does not use packet switching.
The following reference(s) were/was used to create this question:
The CISCO Wiki on Frame Relay