checked list box items checked

I assume ,

1) It is a Windows application
2) You have a ComboBox with 10items.
3) You have CheckedListBox with 20items and
4) The business is, Every item selection from the ComboBox will check associate CheckedListBox items, for example,

Item1 =>{ Option1, Option2 }
Item2 =>{ Option1, Option2,Option4 } etc.

Following code might help you,

namespace Gui_ComboBox
{
    using System.Linq;
    using System.Windows.Forms;
    public partial class frmMain : Form
    {

        private Dictionary<string, string> StrategyOfSelection = new Dictionary<string, string>()
        {
            {"Item1","Option1,Option2"},
            {"Item2","Option3,Option5,Option3,Option11"},
            {"Item3","Option3,Option5,Option9,Option6"},
            {"Item4","Option4,Option7,Option14,Option8,Option6"},
            {"Item5","Option3,Option5,Option8,Option13,Option15,Option17"}
            // So On...
        };
        public frmMain()
        {
            InitializeComponent();
        }

        private void cbSelector_SelectedIndexChanged(object sender, EventArgs e)
        {
            UnCheckedAll();
            if (StrategyOfSelection.Keys.Contains(cbSelector.SelectedItem.ToString()))
            {
                string[] optionsToSelect = StrategyOfSelection[cbSelector.SelectedItem.ToString()].Split(new char[] { ',' });
                foreach (string item in optionsToSelect)
                {
                    clbOptions.SetItemChecked(clbOptions.FindStringExact(item), true);
                }
            }
        }

        private void UnCheckedAll()
        {
            for (int i = 0; i < this.clbOptions.Items.Count; ++i)
                clbOptions.SetItemChecked(i, false);
        }
    }
}

:)