How many trusts should you identify?

Your network contains four Active Directory forests. Each forest contains an Active Directory
Rights Management Services (AD RMS) root cluster.
All of the users in all of the forests must be able to access protected content from any of the
forests.
You need to identify the minimum number of AD RMS trusts required.
How many trusts should you identify?

A.
3

B.
6

C.
12

D.
16