You are designing an n-tier .NET Framework 4 solution that includes a Windows Presentation Foundation (WPF) application. The WPF application will access data stored in a Microsoft SQL Server 2008 database by using the solution’s data access tier.

The data access tier must also be available from within Microsoft Excel 2010.

You need to recommend a technology for accessing the data access tier.

Which technology should you recommend?

A.
ADO.NET Entity Framework 4

B.
LINQ to SQL

C.
WCF Data Services

D.
LINQ to XML

Explanation:
ADO.NET Entity Framework 4 http://stackoverflow.com/questions/7385907/update-db-from-excel-with- entity-framework-4-1
LINQ to SQL http://stackoverflow.com/questions/376524/populate-excel-with-data-from-linq-to-sql-query (Sending individual OLE commands for each Excel cell is very slow) WCF Data Services http://damianblog.com/2009/07/05/excel-wcf/ LINQ to XML http://blogs.msdn.com/b/bethmassi/archive/2007/10/30/quickly-import-and-export-excel-data- with-linq-to-xml.aspx ( import export)
The parts of ADO.NET Data Services that were focused on the Windows implementation of OData are now WCF Data Services.
known as wcf and sql http://damianblog.com/2009/07/05/excel-wcf/