C#

Columns ->    Invoice No   Customer    Date      ItemsCost     VAT   TotalInvoiced
Rows                1001   Smiths    2016/12/14     102.37   20.47          122.84
  |                 1002   Johnson   2016/12/15    1247.99    ... 
  V                 1003   Smiths    2016/12/15     742.65    ... 
                    ...

string[] Answers = new string[4];
//
//Code to load answers into array
//
string UserChoice = Answers[IndexOfChoice];

int QuesionCount;
        int IndexOfChoice;
        DataTable dt = new DataTable();
        int[] Answers = new int[4];
        string cs= @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=c:\users\pavle\documents\visual studio 2015\Projects\Ko zna zna\Ko zna zna\Koznazna.mdf;Integrated Security=True";
        private void Form1_Load(object sender, EventArgs e)
        {
            using (SqlConnection connection = new SqlConnection(cs))
            {
                string query = "SELECT * FROM Pitanja ORDER BY NEWID()";
                SqlCommand command = new SqlCommand(query, connection);
                try
                {
                    connection.Open();
                    dt.Load(command.ExecuteReader());
                    connection.Close();
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }  
            }
            setQuestion();
        }

        private void provera()
        {
            int UserChoice = Answers[IndexOfChoice];
            if (answer_id == UserChoice)
            {
                MessageBox.Show("Odgovor je tacan!");
            }
            else
            {
                MessageBox.Show("Odgovor nije tacan!");
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Answers[IndexOfChoice] = 1;
            provera();  
        }
       
        private void button2_Click(object sender, EventArgs e)
        {
            Answers[IndexOfChoice] = 2;
            provera();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            Answers[IndexOfChoice] = 3;
            provera();
        }

        private void button4_Click(object sender, EventArgs e)
        {
            Answers[IndexOfChoice] = 4;
            provera();
        }

        private void button5_Click(object sender, EventArgs e)
        {
            try
            {
                this.QuesionCount++;
                setQuestion();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        int answer_id;
        private void setQuestion()
        { 
            try
            {
                this.label2.Text = this.dt.Rows[this.QuesionCount]["Pitanje"].ToString();
                this.button1.Text = this.dt.Rows[this.QuesionCount]["OpcijaA"].ToString();
                this.button2.Text = this.dt.Rows[this.QuesionCount]["OpcijaB"].ToString();
                this.button3.Text = this.dt.Rows[this.QuesionCount]["OpcijaC"].ToString();
                this.button4.Text = this.dt.Rows[this.QuesionCount]["OpcijaD"].ToString();
                
                this.label3.Text = this.dt.Rows[this.QuesionCount]["Odgovor"].ToString();        
                answer_id = Convert.ToInt32(this.dt.Rows[this.QuesionCount]["Odgovor"]);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }