You have a single Active Directory Domain Services forest that consists of a single domain named contoso.com. Your company has a business partner named Tailspin Toys. Tailspin Toys has its own Active Directory Domain Services forest that contains a single domain named tailspintoys.com. An application named App1 is available to users in the Domain Users group in the contoso.com domain. You need to make App1 available to users in the Domain Users group in the tailspintoys.com domain. What should you do?

A.
Configure the tailspintoys.com domain to trust the contoso.com domain.

B.
Configure the contoso.com domain to trust the tailspintoys.com domain.

C.
Configure the Account Authority to be tailspintoys.com.

D.
Deploy Active Directory Federation Services in the environment.