Combo box A to combo box B filtering starting characters match from Combo Box A to Combo Box B

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

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

        private string[] table2 = new string[] { "12", "23", "3456", "456" };

        private void comboBoxA_SelectedIndexChanged(object sender, EventArgs e)
        {
            // Find filter char
            char selectedChar = comboBoxA.Text[0];

            // Clear combo box
            comboBoxB.SelectedIndex = -1;
            comboBoxB.Items.Clear();

            // Repopulate by selected char
            for (int i = 0; i < table2.Length; i++)
            {
                if (table2[i][0] == selectedChar)
                {
                    comboBoxB.Items.Add(table2[i]);
                }
            }
        }
    }
}