All client computers in your company run Windows 7. Windows Virtual PC is installed on all client computers. You create and configure a virtual machine (VM) named Guest1. You need to use the Guest1 virtual hard disk (VHD) as a base for additional VMs that will run on the same host computer, and minimize the disk space required for each new VM. Which type of VHD should you create for the new VMs？（）

• A、fixed size
• B、differencing
• C、dynamically expanding
• D、linked to a physical hard disk