You have a portable computer that runs Windows 7. The computer is joined to a domain. Multiple users logon to the computer. You need to prevent the computer from displaying the username of the last user whologged on. What should you do？（）
- AFrom Control Panel， modify the User Profiles settings.
- BFrom Control Panel， modify the Personalization settings.
- CFrom the local computer policy， add a policy template.
- DFrom the local computer policy， modify the local security policy.