You need to ensure that users in the company1

Your network consists of two Active Directory forests. The Active Directory forests are configured as shown in the following table:

The contoso.com and fabrikam.com domains each contain one server that runs Active Directory Federation Services (AD FS).
Users in the company1.contoso.com domain require access to an application server in the company2.fabrikam.com domain.
The application server is configured to allow only Kerberos authentication.

You need to ensure that users in the company1.contoso.com domain can access the application server in the company2.fabrikam.com domain.

What should you do first?

A.
Create a forest trust between the contoso.com forest and the fabrikam.com forest.

B.
Create an external trust between the contoso.com domain and the fabrikam.com domain.

C.
Create an AD FS federation trust between the contoso.com forest and the fabrikam.com forest.

D.
Create an external trust between the company1.contoso.com domain and the company2.fabrikam.com domain.