ComboBox Shows System.Data.DataRow (MVC)

My Combobox does not show me the values in my SQL-Attribute "TimeBlock", instead it shows System.Data.DataRow 5 Times. What is wrong with my code?

Code:

    //DAL:

    public class DAL{

    string ConnectionString = "server=ICSSQL13\\Grupp28,1528; Trusted_Connection=yes; database=Yoloswag";

    public DataTable StoreSqlDataInComboBoxTP()
            {

                SqlConnection Conn = new SqlConnection(ConnectionString);

                Conn.Open();

                string StoreSqlDataInComboBoxTP = "SELECT TimeBlock FROM TimePeriod GROUP BY TimeBlock";

                SqlCommand Cmd = new SqlCommand(StoreSqlDataInComboBoxTP, Conn);

                SqlDataAdapter Adapter = new SqlDataAdapter(Cmd);

                DataSet DSet = new DataSet();

                Adapter.Fill(DSet);

                Adapter.Dispose();
                Cmd.Dispose();
                Conn.Close();
                Conn.Close();

                return DSet.Tables[0];
            }
    }

    //Controller:

    public class Controller
    { 
    DAL Dal = new DAL();

    public DataTable storesqldataincomboboxtp()
        {
           return Dal.StoreSqlDataInComboBoxTP();
        }
    }

//View:
public partial class Booking : Form
    {
        Controller controller = new Controller();
        DataTable DTable = new DataTable();
        DataSet DSet = new DataSet();

        //Ignore string UserName
        public Booking(string UserName){
            DTable = controller.storesqldataincomboboxtp();

            if (DTable.Rows.Count > 0)
            {
                for (int i = 0; i < DTable.Rows.Count; i++)
                {
                    CBTime.Items.Add(DTable.Rows[i].ToString());
                }
            }
         }
     }

Instead of the 5 System.Data.DataRow I want to show what is stored in "TimeBlock". "SELECT TimeBlock From TimePeriod GROUP BY TimeBlock" shows: "08-00 - 10:00" "10:00 - 12:00" "12:00 - 14:00" "14:00 - 16:00" "16:00 - 18:00"

How can i solve this?

Thanks

You are not getting to the Field level when you are calling the Add() on CBTime. Something like this within your conditional checking that your table has rows would work:

foreach (DataRow dRow in DTable.Rows)
{
     CBTime.Items.Add(dRow["TimeBlock"]);
}