how to selected dropdown value in angularjs

HTML:

<div ng-app>
    <h2>TAsk Details</h2>
    <div ng-controller="TodoCtrl">
        <select ng-model="ddlRooms" ng-options="r.id as r.Name for r in Rooms">
        </select>
        {{$scope.test}}
    </div>
</div>
Angular

function TodoCtrl($scope) {
    $scope.Rooms = [{ Name: 'Toddler', id: 1 },{ Name: 'other', id: 2 }];
    $scope.options = [{ Name: 'other', id: 2 }];
    $scope.ddlRooms = $scope.options[0];

    $scope.test = 'bla';
}