The annualized loss expectancy (ALE) is the product of the annual rate of occurrence (ARO) and the single loss expectancy (SLE). It is mathematically expressed as: ALE = ARO x SLE Single Loss Expectancy (SLE) is mathematically expressed as: Asset value (AV) x Exposure Factor (EF) Thus if SLE = $ 24,000 and EF = 25% then the Asset value is SLE/EF = $ 96,000 References:
http://www.financeformulas.net/Return_on_Investment.html
https://en.wikipedia.org/wiki/Risk_assessment

The first thing you should do is verify the reliability of the claims. From there you can assess the likelihood of the vulnerability affecting your systems. If it is determined that your systems are likely to be affected by the exploit, you need to determine what impact an attack will have on your hosted data. Now that you know what the impact will be, you can test the exploit by using the proof-of-concept code. That should help you determine your options for dealing with the threat (remediation).
Incorrect Answers:
B: While penetration testing your system is a good idea, it is unnecessary to hire an independent security consulting agency to perform a penetration test of the web servers. You know what the vulnerability is so you can test it yourself with the proof-of-concept code.
C: Security response should be proactive. Waiting for the threat to be verified by the software vendor will leave the company vulnerable if the vulnerability is real.
D: Bringing down the web servers would prevent the vulnerability but would also render the system useless. Furthermore, customers would expect a certain level of service and may even have a service level agreement in place with guarantees of uptime.
References:
Gregg, Michael, and Billy Haines, CASP CompTIA Advanced Security Practitioner Study Guide, John Wiley & Sons, Indianapolis, 2012, pp. 375-376