You need to ensure that employees can log on to their laptops when they work from home

You support computers that run Windows 8 Enterprise. Your company protects all laptops by using the
BitLocker Network Unlock feature. Some employees work from home.
You need to ensure that employees can log on to their laptops when they work from home.
What should you do?

A.
Provide employees their BitLocker PINs.

B.
Ensure that the Trusted Platform Module (TPM) chips in the laptops are version 1.2 or greater.

C.
Enable BitLocker To Go.

D.
Have users run the Manage-bde.exe -unlock commandbefore they disconnect from the company network.

Explanation:
Original answer was ‘D’ but, this would require an elevated command prompt.
What is a BitLocker Drive Encryption startup key orPIN?
Reference:
http://windows.microsoft.com/en-US/windows-vista/What-is-a-BitLocker-Drive-Encryption-startup-key-or-PIN

In addition to the option of creating a startup key, you have the option of creating a startup personal
identification number (PIN). You can create either the startup key or the startup PIN, but not both. The startup
PIN can be any number that you choose from 4 to 20 digits in length. The PIN is stored on your computer. You
will have to type the PIN each time you start the computer.