All serves on your network run Windows Server 2008 R2. All client computers run Windows
7. You deploy remote desktop Services (RDS).
You are configuring the Remote Desktop Session Host (RD Session Host) role services.
You need to configure the RD Session Host Servers to ensure that all communication
between client computers and servers users 128-bit encryption.
What should you do?

A.
In the Group Policy Object Editor, configure the Set client encryption level setting to the
FIPS Compliant.

B.
In the RD Session Host Configuration tool, require the SSL (TLS 1.0) security layer.

C.
In the RD Session Host Configuration tool, require the RDP security layer.

D.
In the Group Policy Object Editor, configure the set client encryption level setting to high.

Explanation:
http://technet.microsoft.com/en-us/library/cc770833
As clients are all Windows 7, Defaults to Highest supported encryption, however you must
force 128-bit which is equivalent to Group Policy setting High.
SSL 1.0 is greater than 128-bit encryption and requires a certificate.