Which process can you use to start up a Mac in target disk mode?
A. Start up from the OS X Recovery partition, choose Target Disk Mode from the Startup Disk menu, then restart the Mac.
B. Hold down the S key as the Mac starts up, then enter the command shutdown -r -target.
C. Restart your Mac, then hold down the T key as the Mac starts up.
D. Hold down the Option key as the Mac starts up, until a dialog appears, then select Target Disk Mode from the dialog.