Your company has a main office and a branch office. The network contains an Active Directory forest. The forest contains three domains. The branch office contains one domain controller named DC5. DC5 is configured as a global catalog server， a DHCP server， and a file server. You remove the global catalog from DC5. You need to reduce the size of the Active Directory database on DC5. The solution must minimize the impact on all users in the branch office. What should you do first（）
- AStart DC5 in Safe Mode.
- BStart DC5 in Directory Services Restore Mode.
- COn DC5， start the Protected Storage service.
- DOn DC5， stop the Active Directory Domain Services service.