You are maintaining a Microsoft ASP.NET Web Application that was created by using the Microsoft .NET Framework version 3.5.  You obtain the latest version of the project from the source control repository. You discover that an assembly reference is missing when you attempt to compile the project on your computer. You need to compile the project on your computer.  What should you do？（）

• A、A
• B、B
• C、C
• D、D