Because you do not know the IT organizations that you might acquire, you can start with an ADFS 2.0 federation provider. You may, however, soon find this onerous to maintain, particularly if your partner organizations are as small as you expect.
Consider proposing a system whereby you use the Windows Azure ACS instead to allow for the centralized management of all federation efforts within your company.
Correct answers: C, D
Incorrect: Although basic authentication is a Windows authentication type, it is not integrated enabling user names and passwords to be passed through automatically.
Incorrect: Forms authentication relies on ASP.NET and a back-end database to maintain authentication ...