What feature integrates query language directly into C# applications?

LINQ, which stands for Language Integrated Query, is a powerful feature of C# that allows developers to write queries directly in the C# language syntax. This integration enables seamless querying of different data sources, such as collections, databases, and XML, while maintaining the benefits of type safety and IntelliSense provided by C#.

With LINQ, developers can use familiar C# constructs like lambda expressions and method syntax, making it easier to work with data in a more expressive and readable manner. This integration enhances productivity by allowing developers to work with their data using the same language they are coding in, rather than switching between different query languages.

Other options, while related to data access and management in some context, do not provide the same level of integration of query language directly into C# applications. ADO.NET is primarily a set of classes for data access, the Entity Framework is an Object-Relational Mapping (ORM) framework that facilitates database interactions, and SQL Server Management Studio is a tool for managing SQL Server databases, not a programming feature.