XML C#

/*


    C#
    
        A
        B
    

    8.99

*/
using System;
using System.Linq;
using System.Xml;
using System.Xml.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml.XPath;
public class MainClass{
   public static void Main(){
            
        XPathDocument document = new XPathDocument("domainBooks.xml");
        XPathNavigator navigator = document.CreateNavigator();
        
        navigator.MoveToChild("bookstore", "http://www.domain.com/books");
        navigator.MoveToChild("book", "http://www.domain.com/books");
        
        XmlWriter writer = XmlWriter.Create("domainBook.xml");
        navigator.WriteSubtree(writer);
        
        writer.Close();
   }
}