Joseph enabled FileVault 2. He then forgot the administrator password. How can you help Joseph?
A . Ask Joseph to startup from OS X Recovery and choose
B . Have Joseph startup from OS X Recovery and open the Firmware Password utility
C . Explain to Joseph that he can unlock the disk using the recovery key created when FileVault 2 was enabled.
D . Help Joseph erase the hard disk and reinstall OS X and forgotten.
Answer: B
Explanation: https://discussions.apple.com/thread/4910616