如何在格式angularjs中默认选择单选按钮

<div ng-app="myApp" ng-controller="myCtrl">
  <label>
    <input type="radio" ng-model="selectedOption" ng-value="option1" ng-checked="selectedOption === 'option1'"> Option 1
  </label>
  <label>
    <input type="radio" ng-model="selectedOption" ng-value="option2" ng-checked="selectedOption === 'option2'"> Option 2
  </label>
  <label>
    <input type="radio" ng-model="selectedOption" ng-value="option3" ng-checked="selectedOption === 'option3'"> Option 3
  </label>
</div>

<script>
  var app = angular.module('myApp', []);
  app.controller('myCtrl', function($scope) {
    $scope.selectedOption = 'option2'; // 默认选择Option 2
    $scope.option1 = 'option1';
    $scope.option2 = 'option2';
    $scope.option3 = 'option3';
  });
</script>