Explanation/Reference:
Scenario:
Contoso is forming a new corporation namedProseware, Inc. that will sell SharePoint apps. The company has acquired the proseware.com domain name.
Contoso is preparing to federate with Microsoft Office 365 and will use the proseware.com domain for Office 365 services.
The network infrastructure contains an Active Directory Domain Services (AD DS) environment. All servers run Windows Server 2008 R2. The internal AD DS domain is named contoso.com. Active Directory Federation Services (AD FS) is deployed in the LAN. Two AD FS proxy servers are deployedin the perimeter network.
Office 365 must use single sign-on (SSO).
This is difficult to answer because none of the answers is a complete answer. We do need to add proseware.com as an Office 365 SSO domain. However, as the users log in using
[email protected], we would also have to configure the user accounts with a UPN of proseware.com.
Answer B is also incomplete as you would still need the users to log in using
[email protected].