Jessie is trying to boot to OS X Recovery. She remembers using OS X Recovery in the past on this
computer, but she does not see the Recovery HD in Startup Manager anymore. Of the following
possibilities, which is most likely the cause?

A.
There is no Recovery HD.

B.
Disable Recovery HD is selected in the Startup Disk pane of System Preferences.

C.
OS X Yosemite needs to be reinstalled from App store.

D.
FileVault 2 is enabled or a firmware password is set.