The correct answer is IPSec. The SPI, AH and/or ESP and the destination
IP address are components of an IPSec Security Association (SA.)
The other answers describe protocols other than IPSec.

The IPsec protocol suite operates at the network layer of the OSI model. It runs directly on top of IP (the Internet Protocol), which is responsible for routing data packets. Meanwhile, SSL operates at the application layer of the OSI model.

Emergency management plans, business continuity plans, and disaster recovery plans should be regularly reviewed, evaluated, modified, and updated. At a minimum, the plan should be reviewed at an annual audit. It should also be re-evaluated: After tests or training exercises, to adjust any discrepancies between the test results and the plan After a disaster response or an emergency recovery, as this is an excellent time to amend the parts of the plan that were not effective When personnel, their responsibilities, their resources, or organizational structures change, to familiarize new or reorganized personnel with procedures When polices, procedures, or infrastructures change Source: Emergency Management Guide for Business and Industry Federal Emergency Management Agency, August, 1998 and NFPA 1600 Standard on Disaster/Emergency Management and Business Continuity National Fire Protection Association, 2000 edition.

Explanation/Reference:
Explanation:
In a Smurf Attack the attacker sends an ICMP ECHO REQUEST packet with a spoofed source address to a victim's network broadcast address. This means that each system on the victim's subnet receives an ICMP ECHO REQUEST packet. Each system then replies to that request with an ICMP ECHO REPLY packet to the spoof address provided in the packets-which is the victim's address. All of these response packets go to the victim system and overwhelm it because it is being bombarded with packets it does not necessarily know how to process. The victim system may freeze, crash, or reboot.
Incorrect Answers:
B: A fraggle attack is a variation of a Smurf attack where an attacker sends a large amount of UDP traffic to ports 7 (echo) and 19 (chargen) to an IP Broadcast Address, with the intended victim's spoofed source IP address.
C: A LAND attack involves sending a spoofed TCP SYN packet (connection initiation) with the target host's IP address to an open port as both source and destination. This causes the machine to reply to itself continuously.
D: A replay attack (also known as playback attack) is a form of network attack in which a valid data transmission is maliciously or fraudulently repeated or delayed. This is carried out either by the originator or by an adversary who intercepts the data and retransmits it.
References:
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 587

Asynchronous Communication transfers data by sending bits of data in irregular timing patterns. In asynchronous transmission each character is transmitted separately, that is one character at a time. The character is preceded by a start bit, which tells the receiving end where the character coding begins, and is followed by a stop bit, which tells the receiver where the character coding ends. There will be intervals of ideal time on the channel shown as gaps. Thus there can be gaps between two adjacent characters in the asynchronous communication scheme. In this scheme, the bits within the character frame (including start, parity and stop bits) are sent at the baud rate.
The START BIT and STOP BIT including gaps allow the receiving and sending computers to
synchronise the data transmission. Asynchronous communication is used when slow speed
peripherals communicate with the computer. The main disadvantage of asynchronous
communication is slow speed transmission. Asynchronous communication however, does not
require the complex and costly hardware equipments as is required for synchronous transmission.
Asynchronous communication is transmission of data without the use of an external clock signal.
Any timing required to recover data from the communication symbols is encoded within the
symbols. The most significant aspect of asynchronous communications is variable bit rate, or that
the transmitter and receiver clock generators do not have to be exactly synchronized.
The asynchronous communication technique is a physical layer transmission technique which is
most widely used for personal computers providing connectivity to printers, modems, fax
machines, etc.
An asynchronous link communicates data as a series of characters of fixed size and format. Each
character is preceded by a start bit and followed by 1-2 stop bits.
Parity is often added to provide some limited protection against errors occurring on the link.
The use of independent transmit and receive clocks constrains transmission to relatively short
characters (<8 bits) and moderate data rates (< 64 kbps, but typically lower).
The asynchronous transmitter delimits each character by a start sequence and a stop sequence.
The start bit (0), data (usually 8 bits plus parity) and stop bit(s) (1) are transmitted using a shift
register clocked at the nominal data rate.
When asynchronous transmission is used to support packet data links (e.g. IP), then special
characters have to be used ("framing") to indicate the start and end of each frame transmitted.
One character (none as an escape character) is reserved to mark any occurrence of the special
characters within the frame. In this way the receiver is able to identify which characters are part of
the frame and which are part of the "framing".
Packet communication over asynchronous links is used by some users to get access to a network
using a modem.
Most Wide Area Networks use synchronous links and a more sophisticated link protocol
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten
Domains of Computer Security, 2001, John Wiley & Sons, Page 100.
and
http://en.wikipedia.org/wiki/Asynchronous_communication
and
http://www.erg.abdn.ac.uk/users/gorry/course/phy-pages/async.html
and
http://www.ligaturesoft.com/data_communications/async-data-transmission.html