What should you install?

You plan to stream media content over the Internet.

You need to configure PlayReady DRM to support HTTP streaming.

What should you install?

A.
Microsoft IIS Media Services

B.
Microsoft Office Communications Server

C.
Microsoft SharePoint Foundation 2010

D.
Streaming Media Services

Explanation:
IIS Media Services to Include a Version of PlayReady DRM for HTTP Streaming

Some big news today for customers who are interested in easy to use, robust content protection for HTTP streaming scenarios using IIS Media Services
Today were announcing that IIS Media Services will support a version of PlayReady DRM to enable protected HTTP streaming. The PlayReady DRM IIS Media Services solution will deploy on a single box to secure your media assets for online streaming using the IIS Smooth Streaming and PlayReady DRM technology, directly within IIS Media Services – no additional license fees or royalties required.
File-based encryption is the most robust way to secure high value content much more so than stream encryption, which only secures the communication stream. The PlayReady DRM IIS Media Services solution will bring full file-based encryption into IIS Media Services with the ease of use of traditional stream encryption. And the solution of course will use Microsoft PlayReady technology, which is widely supported in the industry and draws on the experience gained from more than a decade of investment that Microsoft has made in the development of DRM technology.
For customers needing to apply PlayReady DRM protection to content for offline scenarios, or apply customized business rules to the use of protected content in purchase/rental/subscription scenarios, of course that functionality will remain available, as it is today, via the use of a PlayReady Server.

Source: http://team.silverlight.net/announcement/iis-media-services-to-include-a-version-of-playready-drm-for-http-streaming/