You work as an ASP.NET Web Application Developer for SomeCompany. The company uses Visual Studio .NET 2010 as its application development platform. You create an ASP.NET Web application using .NET Framework 4.0. The Web application connects to a SQL Server database. You use the ADO.NET Entity Framework to handle persistence-ignorant entities. You create an ObjectContext object named ObjContext. Subsequently， you change properties on numerous entities. You are required to save the changed entity values in the SQL Server database. Which of the following code segments will you use？（）
- AObjContext.SaveChanges（SaveOptions.DetectChangesBeforeSave）；
- BObjContext.SaveChanges（SaveOptions.AcceptAllChangesAfterSave）；
- CObjContext.SaveChanges（SaveOptions.All）；
- DObjContext.SaveChanges（SaveOptions.None）；