Angular服务不会触发

我做了非常简单的plunker来显示我的问题。问题是我有一个变量，我想用初始应用加载来填充这个变量，为此我做了angular services，但由于某种原因，angular services没有在控制器内部触发。我错在哪里?

app.controller('MainCtrl', function($scope, optService) {
  $scope.priority = [];
  var exeService = function() {
    console.log('function fired')
     // this is firing
      optService.myOptions(function (result) {
        console.log('service fired')
     // this is not firing
          angular.forEach(result, function(value) {
              $scope.priority.push({value: value.name, label: value.name});
          });
      });
   }
  exeService()
  console.log($scope.priority)
  // shows an empty array
});

(function () {
angular.module("app").factory("optService", ["$http", "$rootScope", "$q", "$log",
    function ($http, $rootScope, $q, $log) {
        var clearApi = "test.json";

        function myOptions () {
            return $http.get(clearApi)
                .then(function (response) {
                  console.log(response.data)
                  // shows an array
                    return response.data;
                });
        } 
        return {
          myOptions: myOptions
        }
        }])
}());