Query XML with XPath Syntax in CSharp

using System;/*from w w  w. j  a v a2  s.  c o  m*/
using System.IO;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using System.Xml.XPath;
using System.Xml.Schema;
using System.Xml.Linq;
public class MainClass {
    public static void Main() {
        XDocument xDocument = new XDocument(
          new XElement("Books",
            new XElement("Book",
              new XAttribute("type", "Author"),
              new XElement("FirstName", "A"),
              new XElement("LastName", "B")),
           new XElement("Book",
              new XAttribute("type", "Author"),
              new XElement("FirstName", "C"),
              new XElement("LastName", "D"))));

        XElement bookParticipant = xDocument.XPathSelectElement("//Books/Book[FirstName='A']");
        Console.WriteLine(bookParticipant);
    }
}