angularjs - Ng-option directive cant get access to nested array value -

help

i'm trying output different class options(economy/business) ng-options. here syntax , json information . cant working

<select ng-model="myselect" ng-options="item item in items "> </select> 

  $scope.items = [    {     "id": 2,     "codename": "class",     "friendlyname": "class",     "options":      [        {         "id": 15,         "displayorderno": 0,         "optionname": "economy"       },        {         "id": 16,         "displayorderno": 1,         "optionname": "business"       },        {         "id": 36,         "displayorderno": 2,         "optionname": "first class "       }     ]    }   ];