Bring only data with checkbox true

Hi, I'm passing data from one datagridview to another and it happens to me, but when I detect a single checkbox, it brings me all and leaves the checkie, but I want it to only bring me the one that is palomeado and not all of its group

This is the code of my Add button

  private void btnAgregr_Click(object sender, EventArgs e)
    {
        var rowsSelected = this.DataKitchenArea.AsEnumerable().Where(r => Convert.ToBoolean(r["Sel"]));
        foreach (DataRow rowOrigen in rowsSelected)
        {
            DataRow rowDestino = this.DataTableSection.NewRow();
            rowDestino["Sel"] = rowOrigen["Sel"];
            rowDestino["Id"] = rowOrigen["Id"];
            rowDestino["Nombre"] = rowOrigen["Nombre"];
            this.DataTableSection.Rows.Add(rowDestino);
        }
        this.DataGridViewSelectionArea.BindDataGridView(this.DataTableSection);
        }