C++ Quiz Form10

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;

namespace WindowsFormsApplication3
{
    public partial class Form10 : Form
    {
        public Form10()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.Visible = true;
            Form2 form2 = new Form2();
            DialogResult dialog = MessageBox.Show("Answer is not correct! Do you want to play again?", "Quiz", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
            if (dialog == DialogResult.Yes)
            {
                this.Visible = false;
                form2.Show();
            }
            else if (dialog == DialogResult.No)
            {
                //e.Cancel = true;
                Application.Exit();
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            this.Visible = false;
            Form11 form11 = new Form11();
            form11.Show();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            this.Visible = true;
            Form2 form2 = new Form2();
            DialogResult dialog = MessageBox.Show("Answer is not correct! Do you want to play again?", "Quiz", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
            if (dialog == DialogResult.Yes)
            {
                this.Visible = false;
                form2.Show();
            }
            else if (dialog == DialogResult.No)
            {
                //e.Cancel = true;
                Application.Exit();
            }
        }

        private void button4_Click(object sender, EventArgs e)
        {
            this.Visible = true;
            Form2 form2 = new Form2();
            DialogResult dialog = MessageBox.Show("Answer is not correct! Do you want to play again?", "Quiz", MessageBoxButtons.YesNo, MessageBoxIcon.Information);
            if (dialog == DialogResult.Yes)
            {
                this.Visible = false;
                form2.Show();
            }
            else if (dialog == DialogResult.No)
            {
                //e.Cancel = true;
                Application.Exit();
            }
        }
    }
}