disable selected option from one select box when selected in another select box code example

Example: disable other options in select except the selected

$("#lbCountries").click(function () {
     $("#lbCountires option").each(function (index) {
        if ($(this).is(':selected')) {
            $(this).prop('disabled', false);
         }
         else {
            $(this).prop('disabled', true);
         }
      });
  });