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You are analyzing a Windows client application that uses Microsoft Visual Studio 2010 and Microsoft SQL Server 2008.
The application updates two database tables from the main user interface (UI) thread.
You need to ensure that the following requirements are met:
The database tables are either updated simultaneously or not updated at all.
Users are notified of the success or failure of the updates.
Users are able to perform other tasks during the update process.
What should you do?

• A. Use TransactionScope in a Using block on the UI thread.
  Create a DependentTransaction object within the block and pass the object to the BackgroundWorkerReportProgress method.
  Use the object in the ReportProgress method to create a new TransactionScope block.
• B. Use TransactionScope in a Using block on the UI thread.
  Batch the database updates by setting the DbDataAdapter.UpdateBatchSize property to 2.
• C. Use TransactionScope in a Using block on the main thread.
  Create a BackgroundWorker thread within the block.
  Move the database updates to the BackgroundWorkerDoWork method.
• D. Move the database update logic to a BackgroundWorker thread.
  Ensure that the thread is enclosed in a TransactionScope Using block in the BackgroundWorkerDoWork method.

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You are designing a .NET Framework 4 solution. The solution contains a Windows Presentation Foundation (WPF) application and a Windows Communication Foundation (WCF) Web service.
The WPF application uses the WCF Web service to store data in a Microsoft SQL Server 2008 database.
You have the following requirements:
Ensure that the WPF application functions while users' computers are offline.
Minimize the time spent sending data to the WCF Web service.
Minimize disk space requirements for data storage.
You need to recommend an approach for synchronizing data between the WPF application and the database.
Which two actions should you recommend? (Each correct answer presents part of the solution. Choose two.)

• A. Store data in custom business objects. Serialize data locally by using custom serialization.
• B. Store data in DataSet objects. Serialize data locally by using XML serialization.
• C. Create a local caching solution that periodically checks for Internet connectivity, uses local memory, and batches changes to the WCF Web service.
• D. Create a local caching solution that periodically checks for Internet connectivity and writes directly to the local data store and to the WCF Web service.

You are designing an n-tier Windows application by using Microsoft .NET Framework 4, Microsoft Visual Studio 2010, and Microsoft SQL Server 2008.
The application will replace an existing client/server application. The existing application was created by using Microsoft Visual Basic 6.0 and consists of a series of COM components that access a SQL Server database.
You plan to move the existing COM components into a Windows Communication Foundation (WCF) tier.
You need to ensure that the COM components can be replaced without impacting the existing user interface (UI) tier.
You also need to ensure that the COM components can be replaced separately.
What should you do?

• A. Use .NET COM Interop on the client tier to interact directly with the COM components until they are replaced by the managed code.
• B. Convert the Visual Basic 6.0 source code to managed code by using the Visual Studio converters. Use these code components on the client/server application until they are replaced individually with the new permanent managed code functionality.
• C. Create a common assembly on the UI tier of the new application to interface with the COM components.
• D. Create a common assembly on the WCF tier of the new application to interface with the COM components.

You are designing a Windows Presentation Foundation (WPF) application by using Microsoft .NET Framework 4, Microsoft Visual Studio 2010, and Microsoft SQL Server 2008.
You have designed the application to use the ADO.NET Entity Framework for the Data Access Layer (DAL).
You have designed the user interface (UI) of the application by using the Model-View-ViewModel (M-V-VM) pattern.
The middle tier of the application is designed by using Windows Communication Foundation (WCF).
The database schema changes often. The DAL entity objects are required to be referenced from the middle tier and the ViewModel layer of the UI.
You need to ensure that the DAL entity objects are updated when the database schema changes.
What should you do?

• A. Create persistent-ignorant objects.
• B. Create an observable collection of objects.
• C. Create typed DataSets.
• D. Create persistent-aware objects.