While converting XML to JSON using c#, By providing the data within the class,I’m getting the output.I need to fetch data from file present in folder .Could anyone please help on this

Question

using Newtonsoft.Json;
using System;
using System.Windows.Forms;
using System.Xml;

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        
        private void Form1_Load(object sender, EventArgs e)
        {
            XmlDocument doc = new XmlDocument();
            doc.LoadXml(" <Student>\r\n    <Student_Name>Preethi</Student_Name>\r\n    <SSN>45679</SSN>\r\n    <Course>Electronics and communication</Course>\r\n    <Address>\r\n      <Line_1>#1, 6th cross</Line_1>\r\n      <Line_2>Victoria Layout</Line_2>\r\n      <City>Bangalore</City>\r\n      <Country>India</Country>\r\n    </Address>\r\n  </Student>\r\n</Root>");
            string jsonText = JsonConvert.SerializeXmlNode(doc);
            //Console.WriteLine(jsonText);
            MessageBox.Show(jsonText);
        }
    }
}