In .NET, which pair consists only of namespaces that are specifically designed for working with XML data?

Introduction / Context:
The .NET Framework includes many namespaces that organize classes by functionality. When dealing with XML documents, certain namespaces provide readers, writers, document object models, and query capabilities. This question assesses whether you can identify which namespaces are specifically oriented toward XML processing rather than unrelated networking, user interface, or data access tasks.

Given Data / Assumptions:

• The topic is .NET namespaces related to XML.
• Each option lists a pair of namespaces.
• Only one pair is focused directly on XML processing.
• We assume standard .NET Framework or .NET Core libraries.

Concept / Approach:
System.Xml is the traditional namespace containing classes like XmlDocument, XmlReader, and XmlWriter for working with XML data in various ways. System.Xml.Linq contains LINQ to XML classes, such as XDocument and XElement, which provide a modern, query friendly API for XML. Both are central to XML handling in .NET. By contrast, namespaces like System.Net, System.Windows.Forms, System.Data, and System.Drawing are primarily for networking, user interfaces, data access, or graphics, not XML specific tasks. The correct choice must list only System.Xml and System.Xml.Linq.

Step-by-Step Solution:
1. Recall that System.Xml provides core XML classes, including DOM style document manipulation and streaming parsers. 2. Remember that System.Xml.Linq extends XML support by integrating with Language Integrated Query through LINQ to XML. 3. Review each option and check whether the namespaces mentioned are used primarily for XML related operations. 4. Eliminate pairs that include namespaces known for networking, forms, or graphics instead of XML. 5. Select the option that lists only System.Xml and System.Xml.Linq.

Verification / Alternative check:
To verify, think of typical code examples. When you write XmlReader reader = XmlReader.Create, you rely on System.Xml. When you create an XDocument or XElement and query it with LINQ, you include System.Xml.Linq. You do not need namespaces such as System.Net for basic XML parsing, unless you are downloading the XML from a remote server. This confirms that the pair of System.Xml and System.Xml.Linq is the correct XML focused combination.

Why Other Options Are Wrong:

• Option B is wrong because System.Net deals with networking and System.Windows.Forms with desktop user interfaces, not with XML processing specifically.
• Option C is wrong because System.Data focuses on data access and relational data, while System.Drawing is for graphics and images.
• Option D is wrong because System.Web is mainly about web applications, and System.IO is about input and output streams and files, not about XML specific APIs.

Common Pitfalls:
A common pitfall is assuming that any namespace that sometimes interacts with XML is an XML namespace. For example, web applications often send or receive XML, but System.Web is not the core XML processing layer. Another mistake is forgetting that LINQ to XML lives in System.Xml.Linq, not System.Linq alone. Remembering the exact namespaces helps when adding using statements and understanding documentation examples.

Final Answer:
The correct answer is System.Xml and System.Xml.Linq, because both namespaces are explicitly designed to provide classes and methods for working with XML data in .NET applications.