how to make an option disable on select tag code example

Example 1: howt to disable a select tag using js

document.getElementById("one").onchange = function () {
  document.getElementById("two").setAttribute("disabled", "disabled");
  if (this.value == 'car')
    document.getElementById("two").removeAttribute("disabled");
};

Example 2: 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);
         }
      });
  });