You administer a SQL Server 2008 instance. You plan to deploy a third-party database application to the instance. The application uses stored procedures that are developed by using SQL CLR integration. The application must be configured to enable the EXTERNAL_ACCESS code access security setting. You need to ensure that the application is deployed to the instance without loss of functionality. What should you do first?（）

A. Replace read write non-static fields in the code with static fields.
B. Replace read-only static fields in the code with read write static fields.
C. Use the peverify.exe PEVerify tool to verify whether the code meets the type-safety requirements.
D. Use the regasm.exe assembly registration tool to register the assembly on the server before deployment.