JSFiddle - React, Tailwind, and code Playground

HTML

<select id="mySelect">
    <option>Foo0</option>
    <option selected="selected">Foo1</option>
    <option>Foo3</option>
    <option>Foo4</option>
    <option>Foo5</option>
    <option>Foo6</option>
</select>

JavaScript

jQuery(document).ready(function($){
    var select = $('#mySelect');
    var previouslySelected;
    
    select.focus(function(){
        previouslySelected = this.value;
    }).change(function(){
     var conf = confirm('Are You Sure?');
     if(!conf){
         // reset the select back to previous
         this.value = previouslySelected;
         return;
     }

     // do stuff
    alert('Doing stuff');
  });
});