Quiz Tutorial 1 in CS

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;

namespace Exam_System
{
    public partial class frmExam : Form
    {

        string[] saQuestions = new string[100];
        string[] saCurrentQuestion = new string[7];
        int iCurrentQno = 0;
        int iTotalQ = 0;
        string sCurrentCorrectAns = "";

        public frmExam()
        {
            InitializeComponent();
        }

        private void frmExam_Load(object sender, EventArgs e)
        {

            try
            {
                // Create an instance of StreamReader to read from a file.
                // The using statement also closes the StreamReader.
                using (StreamReader sr = new StreamReader("D:\\CStutorial\\Quiz\\q1.txt"))
                {
                    string line;
                    // Read and display lines from the file until the end of
                    // the file is reached.
                    while ((line = sr.ReadLine()) != null)
                    {
                        saQuestions[iTotalQ] = line;
                        iTotalQ = iTotalQ + 1;
                    }
                }
            }
            catch (Exception ex)
            {
               MessageBox.Show (ex.Message);
            }

            saCurrentQuestion  =saQuestions[iCurrentQno].Split('#');
            txtQuestion.Text = saCurrentQuestion[1];
            rdo1 .Text =saCurrentQuestion [2];
            rdo2.Text =saCurrentQuestion [3];
            rdo3.Text =saCurrentQuestion [4];
            rdo4.Text =saCurrentQuestion [5];
            sCurrentCorrectAns = saCurrentQuestion [6];
            iCurrentQno++;
            lblQno.Text = iCurrentQno +"/"+iTotalQ ;
            txtScores.Text = "0";

        }

        private void funMarking()
        {
            if( rdo1.Checked == false && rdo2.Checked == false && rdo3.Checked == false && rdo4.Checked == false )
            {
                MessageBox.Show("Please Choose One Answer");
            }
            else
            {
                int iScore = int.Parse(txtScores.Text);
                if (sCurrentCorrectAns == "1" && rdo1.Checked == true)
                {
                    iScore = iScore + 10;
                }
                else if (sCurrentCorrectAns == "2" && rdo2.Checked == true)
                {
                    iScore = iScore + 10;
                }
                else if (sCurrentCorrectAns == "3" && rdo3.Checked == true)
                {
                    iScore = iScore + 10;
                }
                else if (sCurrentCorrectAns == "4" && rdo4.Checked == true)
                {
                    iScore = iScore + 10;
                }
                txtScores.Text = iScore.ToString();
            }



        }

        private void btnSubmit_Click(object sender, EventArgs e)
        {
            funMarking();
        }
    }
}