Your network has 1，000 client computers that run Windows XP. You are planning to deploy Windows 7. You plan to use the Microsoft Deployment Toolkit Lite Touch Installation deployment method to deploy the Windows 7 image. You have the following requirements： Migrate 20 computers at a time. Ensure that you conserve network bandwidth. You need to design a deployment strategy that meets the requirements. What should you do？（）

A. Configure multicast transmission on the deployment point.
B. Configure unicast transmission on the deployment point.
Compress the contents of the distribution folder.
Distribute the image by using Background Intelligent Transfer Service （BITS）.