How do I list an array into a DropDownList using jQuery AJAX.

var ddl1SelectedValue = $("#<%= DropDownList1.ClientID %> option:selected").val();
var data2 = { "Value2": ddl1SelectedValue };
var json2 = JSON.stringify(data2);
$.ajax
({
    type: "POST",
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    data: json2,
    url: "Default.aspx/BindSubfolder2",
    success: function (result2) {
        $.each(result2, function () {
            $("#<%=DropDownList2.ClientID %>").append($("<option></option>").val(this['RemoteURL']).html(this['RemoteNumber']));
        });
    },
    error: function (status, ex) {
        alert("Error Code: Status: " + status + " Ex: " + ex);
    }
});

Error Code: Status: [object Object] Ex: error

[WebMethod()]
public Cascading2[] BindSubfolder2(string Value2)
{
    List<Cascading2> SubFoldetails2 = new List<Cascading2>();
    DataSet ds = new DataSet();
    try
    {
        using (SqlConnection conn = new SqlConnection(connStr))
        {
            using (SqlCommand cmd = new SqlCommand("Select  [RemoteURL],[RemoteNumber] From [Remote] WHERE RemoteNumber = @RemoteNumber;", conn))
            {
                conn.Open();
                cmd.Parameters.AddWithValue("@RemoteNumber", Value2);
                cmd.ExecuteNonQuery();

                using (SqlDataAdapter da = new SqlDataAdapter(cmd))
                {
                    da.Fill(ds);
                    conn.Close();
                }
            }
        }
        foreach (DataRow DR in ds.Tables[0].Rows)
        {
            Cascading2 cs = new Cascading2();
            cs.RemoteURL = DR["RemoteURL"].ToString();
            cs.RemoteNumber = DR["RemoteNumber"].ToString();
            SubFoldetails2.Add(cs);
        }
    }
    catch (Exception ex)
    {
        Label1.Text = ex.ToString();
    }
    return SubFoldetails2.ToArray();
}

public class Cascading2
{
    public int Remoteid { get; set; }
    public string RemoteNumber { get; set; }
    public string RemoteURL { get; set; }
}