The Internet Security Glossary (RFC2828) defines the Authority Revocation List (ARL) as a data structure that enumerates digital certificates that were issued to CAs but have been invalidated by their issuer prior to when they were scheduled to expire.
Do not to confuse with an ARL with a Certificate Revocation List (CRL). A certificate revocation list is a mechanism for distributing notices of certificate revocations. The question specifically mentions "issued to CAs" which makes ARL a better answer than CRL. http://rfclibrary.hosting.com/rfc/rfc2828/rfc2828-29.asp $ certificate revocation list (CRL)
(I)
A data structure that enumerates digital certificates that have been invalidated by their issuer prior to when they were scheduled to expire. (See: certificate expiration, X.509 certificate revocation list.)
http://rfclibrary.hosting.com/rfc/rfc2828/rfc2828-17.asp $ authority revocation list (ARL)
(I)
A data structure that enumerates digital certificates that were issued to CAs but have been invalidated by their issuer prior to when they were scheduled to expire. (See: certificate expiration, X.509 authority revocation list.)
In a few words: We use CRL's for end-user cert revocation and ARL's for CA cert revocation - both can be placed in distribution points.

Explanation/Reference:
ARP is used to find the Media Access Control address (MAC) that matches with a known Internet Protocol (IP) address.
The Address Resolution Protocol (ARP) is a computer networking protocol for determining a network host's link layer or hardware address when only its Internet Layer (IP) or Network Layer address is known Reverse Address Resolution Protocol (RARP) is used to find the IP address that matches an Ethernet address.
ICMP is a management protocol and messaging service provider for IP (e.g. PING).
UDP runs over IP. It is a best effort protocol that offers no reliability. UDS is used for application such as streaming media, voice over IP, the DNS protocol, as well as the Simple Network Management Protocol (SNMP).
Source: KRUTZ, Ronald L & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 87.
also see:
http://en.wikipedia.org/wiki/Address_resolution_protocol

The reverse address resolution protocol (RARP) sends out a packet including a MAC address and a request to be informed of the IP address that should be assigned to that MAC.
Diskless workstations do not have a full operating system but have just enough code to know how to boot up and broadcast for an IP address, and they may have a pointer to the server that holds the operating system. The diskless workstation knows its hardware address, so it broadcasts this information so that a listening server can assign it the correct IP address.
As with ARP, Reverse Address Resolution Protocol (RARP) frames go to all systems on the subnet, but only the RARP server responds. Once the RARP server receives this request, it looks in its table to see which IP address matches the broadcast hardware address. The server then sends a message that contains its IP address back to the requesting computer. The system now has an IP address and can function on the network.
The Bootstrap Protocol (BOOTP) was created after RARP to enhance the functionality that RARP provides for diskless workstations. The diskless workstation can receive its IP address, the name server address for future name resolutions, and the default gateway address from the BOOTP server. BOOTP usually provides more functionality to diskless workstations than does RARP.
The evolution of this protocol has unfolded as follows: RARP evolved into BOOTP, which evolved into DHCP.
The following are incorrect answers:
NAT is a tool that is used for masking true IP addresses by employing internal addresses. ARP does the opposite of RARP, it finds the MAC address that maps with an existing IP address. Data Link layer The Data Link layer is not a protocol; it is represented at layer 2 of the OSI model. In the TCP/IP model, the Data Link and Physical layers are combined into the Network Access layer, which is sometimes called the Link layer or the Network Interface layer.
Reference(s) used for this question:
Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition, Telecommunications and Network Security, Page 584-585 and also 598. For Kindle users see Kindle Locations 12348-12357. McGraw-Hill. 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 87).

Section: Access Control
Explanation/Reference:
The primary objective of proper separation of duties is to ensure that one person acting alone cannot compromise the company's security in any way. A proper separation of duties does not prevent employees from disclosing information, nor does it ensure that access controls are in place or that audit trails are not tampered with.
Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, Chapter 12:
Operations Security (Page 808).