JSFiddle - React, Tailwind, and code Playground

HTML

<select id="multiSelect" multiple>
  <option value="1">excluded: 1</option>
  <option value="2">excluded: 2</option>
  <option value="3">excluded: 3</option>
  <option value="4">excluded: 4</option>
  <option value="5">excluded: 5</option>
</select>

CSS

select {
  height: 10em;
  width: 10em;
  overflow-y: hidden;
}

JavaScript

document.getElementById("multiSelect").onchange = function() {

  this.childNodes.forEach(function(option) {
  
    if (option.selected === true) {
      option.innerHTML = "SELECTED: " + option.value;
    } else {
      option.innerHTML = "excluded: " + option.value;
    }
    
  });
  
};