问题：

[单选]

Your computer runs Microsoft Windows XP Professional. The computer has the following hardware configuration：
 512 MB of RAM
 1-GHz processor
 60-GB hard disk
 15 GB of free space 
  64-MB video adapter. 
You perform a clean install of Microsoft Windows Vista. 
You need to ensure that Microsoft Windows Aero Experience is supported. 
What should you do？（）

A . Upgrade the memory to 1 GB of RAM.
B . Upgrade the hard disk to 120 GB with 40 GB of free space.
C . Install a video adapter that has 128 MB of RAM， support for Microsoft DirectX 9， and Microsoft Pixel Shader 2.0.
D . Install a video adapter that has 128 MB of RAM， support for Microsoft Scalable Link Interface （SLI） and Microsoft Pixel Shader 2.0.