Your company has a main office and a branch office. The branch office administrators are the only members of a custom management role group. The role group is configured to allow members to manage recipients. You notice that the branch office administrators can manage recipients in both offices. You need to ensure that the branch office administrators can manage recipients in the branch office only. 
What should you do()？ 
 

A.Create and associate a management scope to the role group.
B.Create and associate a management role assignment policy to the role group.
C.Create a new linked role group， and then add the branch office administrators to the role group.
D.Create a new role， and then add management role entries to the role.