You are planning the migration of a Microsoft SQL Server 2008 database to SQL Azure.   You need to recommend an approach for ensuring that database connectivity does not degrade.   Which two actions should you recommend？（）

• A、 Implement transactions for database queries.
• B、 Close database connections in the application.
• C、 Use Microsoft ADO.NET in the data access layer.
• D、 Implement a retry policy in the data access layer.