add a Static option with ng-options angularJS

i ust use ng-options in a select element in angular js. and in select select i just wants to add a extra options at the beginning of options.my code ===>

<div class="form-group">
     <select class="form-control select2" ng-options="(o.fullName+' ('+o.email+')') for o in SubTeamUserList track by o.id" name="SelectedUserList" ng-model="SelectedUserList" multiple data-placeholder="Search By User" style="width: 100%;">
            <option value="" disabled>Select A User</option>
      </select>
</div>

that is not working for me ? i dont know why.then i search on net and found some solution like => angularJS - add a Static option with ng-options Add two extra options to a select list with ngOptions on it Angular ng-options - Is there a way to add an option when the model contains a value not present in the options list?

after see above solutions i tried =>

     <div class="form-group">
        <select class="form-control select2" ng-options="" name="SelectedUserList" ng-model="SelectedUserList" multiple data-placeholder="Search By User" style="width: 100%;">
              <option value="" disabled>Select A User</option>
              <option ng-repeat="(o.fullName+' ('+o.email+')') for o in SubTeamUserList track by o.id">{{(o.fullName+' ('+o.email+')')}}</option>
        </select>
    </div>

after doing this this is also showing something like => but that is also not working for me i dont know why? can anybody help me ???