While Kerberos is the primary mechanism, system administrators
may also use alternative authentication services running under the
Security Support Provider Interface (SSPI). Answer hash
functions, are used for digital signature implementations. Answer SESAME is incorrect. It is the Secure European System for
Applications in a Multivendor Environment. SESAME performs
similar functions to Kerberos, but uses public key cryptography to
distribute the secret keys. Answer "Public key certificates" is incorrect, since public key certificates are not used in the Windows 2000 primary authentication approach.

The correct answer is "To quantify the impact of potential threats". The main purpose of performing a risk analysis is to put a hard cost or value onto the loss of a business function.
The other answers are benefits of risk management but not its
main purpose.

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.