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.