A company named Contoso, Ltd. has an Azure Active Directory (Azure AD) tenant that is integrated with Microsoft Office 365 and an Azure subscription.

Contoso has an on-premises identity infrastructure. The infrastructure includes servers that run Active Directory Domain Services (AD DS), Active Directory Federation Services (AD FS), Azure AD Connect, and Microsoft Identity Manager (MIM).

Contoso has a partnership with a company named Fabrikam, Inc. Fabrikam has an Active Di-rectory forest and an Office 365 tenant. Fabrikam has the same on-premises identity infra-structure as Contoso.

A team of 10 developers from Fabrikam will work on an Azure solution that will be hosted in the Azure subscription of Contoso. The developers must be added to the Contributor role for a resource in the Contoso subscription.

You need to recommend a solution to ensure that Contoso can assign the role to the 10 Fabri-kam developers. The solution must ensure that the Fabrikam developers use their existing cre-dentials to access resources.

What should you recommend?

A. Configure a forest trust between the on-premises Active Directory forests of Contoso and Fabrikam.
B. Configure an organization relationship between the Office 365 tenants of Fabrikam and Contoso.
C. In the Azure AD tenant of Contoso, enable Azure Active Directory Domain Services (Az-ure AD DS). Create a one-way forest trust that uses selective authentication between the Ac-tive Directory forests of Contoso and Fabrikam.

D. In the Azure AD tenant of Contoso, create guest accounts for the Fabrikam developers.

References:
https://docs.microsoft.com/en-us/azure/role-based-access-control/role-assignments-external-users