The Pump (M.h. Kang, I.S. Moskowitz, APump for Rapid, Reliable,
Secure Communications, The 1st ACM Conference on Computer and Communications
Security, Fairfax, VA, 1993) was developed at the US Naval
Research Laboratory (NRL). It permits information flow in one direction only, from a lower level of security classification or sensitivity to a higher level. It is a convenient approach to multilevel security in that it can be used to put together systems with different security levels.
* Answer "A two-way information flow device" is a distracter.
* Answer "Compartmented Mode Workstation (CMW)", the CMW, refers to windows-based workstations that require users to work with information at different classification levels.
Thus, users may work with multiple windows with
different classification levels on their workstations. When data is
attempted to be moved from one window to another, mandatory access
control policies are enforced. This prevents information of a higher classification from being deposited to a location of lower classification.
* Answer "A device that implements role-based access control", role-based access control, is an access control mechanism and is now being considered for mandatory access control based on users' roles in their organizations.

If every one of the 100 clerks makes 1 error 12 times per year, it makes a total of 1200 errors. The Annnualized Rate of Occurence (ARO) is a value that represents the estimated frequency in which a threat is expected to occur. The range can be from 0.0 to a large number. Having an average of 1200 errors per year means an ARO of 1200.

Explanation
Section: Security Assessment and Testing

Historically, a code refers to a cryptosystem that deals with linguistic units:
words, phrases, sentences, and so forth. Codes are only useful for specialized circumstances where the message to transmit has an already defined equivalent ciphertext word.
Source: DUPUIS, Cl?ment, CISSP Open Study Guide on domain 5, cryptography, April
1999.