Which authentication method should you configure?

A company has an Active Directory Domain Services (AD DS) domain. The company has
100 client computers and tablets that run Windows 8. Each user has a unique local user
account on each device he or she uses.
The company wants to simplify the logon process for atl users.
You have the following requirements:
Reduce the number of unique user accounts for each user.
Unify the initial Windows 8 theme across all Windows 8 devices.
Ensure that Windows Store apps maintain the last used state across all Windows 8 devices.
You need to configure an authentication method that meets the requirements.
Which authentication method should you configure?

A.
Pin

B.
Microsoft account

C.
Active Directory user account

D.
Picture password