JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.1.5/angular.min.js"></script>
<div ng-app ng-controller="Controller">
    <select ng-model="myDropDown">
          <option value="one">One</option>
          <option value="two" ng-if="myDropDown=='one'">Two</option>
          <option value="three">Three</option>
    </select>
    
    {{myDropDown}}
</div>

JavaScript

function Controller ($scope) {
$scope.show=true;
    $scope.myDropDown = 'three';
}