Your company purchases an Office 365 plan. The company has an Active Directory Domain Services domain.
User1 must manage Office 365 delegation for the company.
You need to ensure that User1 can assign administrative roles to other users.
What should you do?

A.
Create an Office 365 tenant and assign User1 the password administrator role.

B.
Use a password administrator account to assign the role to User1.

C.
Use a user management administrator account to assign the role to User1.

D.
Create an Office 365 tenant and assign User1 the global administrator role.

Explanation:

Global admin: Has access to all administrative features. Global admins are the only admins who can assign other admin roles. You can have more than one global
admin in your organization. The person who signs up to purchase Office 365 becomes a global admin.
Ref: https://support.office.com/client/Assigning-admin-roles-eac4d046-1afd-4f1a-85fc-8219c79e1504