why dropdown not binding values

Question

<div ng-controller="Part1Controller">

<form name="f1" novalidate ng-submit="SaveData(tab1)">

<div style="color:red">

{{meassage}}

</div>

<table>

<tr>

<td class="headder">Enter Employee Name</td>

<td>

<input type="text" name="tName" ng-model="tab1.Name" ng-class="Submitted? 'ng-dirty':''" required autofocus>

<span class="Error" ng-show="(f1.tName.$dirty ||Submitted ) && f1.tName.$error.required">Please Enter Employee Name</span>

</td>

</tr>

<tr>

<td class="headder">Enter Employee EmailId</td>

<td>

<input type="email" name="tEmail" ng-model="tab1.Email" ng-class="Submitted? 'ng-dirty':''" required />

<span class="Error" ng-show="(f1.tEmail.$dirty ||Submitted ) && f1.tEmail.$error.required">Please Enter Your EmailId</span>

</td>

</tr>

<tr>

<td class="headder">Select Your Gender</td>

<td>

<input type="radio" name="tGen" ng-model="tab1.Gender" value="Male" ng-class="Submitted? 'ng-dirty':''" required />Male

&nbsp;&nbsp; <input type="radio" name="tGen" ng-model="tab1.Gender" value="Fe-Male" ng-class="Submitted? 'ng-dirty':''" required />Fe-Male

<span class="Error" ng-show="(f1.tGen.$dirty ||Submitted ) && f1.tGen.$error.required">Plese Select Your Gender</span>

</td>

</tr>

<tr>

<td class="headder">Enter Password</td>

<td>

<input type="password" name="tpsw" ng-model="tab1.Password" ng-class="Submitted? 'ng-dirty':''" required />

<span class="Error" ng-show="(f1.tpsw.$dirty ||Submitted ) && f1.tpsw.$error.required">Plese Enter Your Passwor</span>

</td>

</tr>

<tr>

<td> Country :</td>

<td>

<select ng-model="tab1.CountryName" ng-options="I.CountryID as I.CountryName for I in countryList">

<option value="">Select Country</option>

</select>

</td>

</tr>

<tr>

<td>

<input type="submit" value="{{SubmitText}}" />

</td>

</tr>

</table>

</form>

</div>

angular.module("MyApp",[])

.controller("Part1Controller", function ($scope, Reserve) {

$scope.tab1 = {

Name: '',

Email: '',

Password: '',

Gender: '',

CountryName: '',

StateName: '',

CityName: '',

Image: '',

Active: ''

};

$scope.meassage = '';

$scope.Submitted = false;

$scope.isFormValid = false;

$scope.SubmitText = "Save";

// $scope.countryList = null;

$scope.StateList = null;

$scope.CitiesList = null;

$scope.CountryID = null;

//watch form is valid or not

$scope.$watch('f1.$valid', function (resdata) {

$scope.isFormValid = resdata;

})

//saving form

$scope.SaveData = function (data) {

if ($scope.SubmitText == "Save") {

$scope.meassage = '';

$scope.Submitted = true;

if ($scope.isFormValid) {

$scope.SubmitText = "please Wait....";

Reserve.SaveFormData($scope.tab1)

.then(function (d) {

alert(d)

if (d == "Sucess") {

clearFormData();

}

})

Reserve.GetCountrys()

.then(function (d) {

$scope.countryList = d.data;

}, function (error) {

alert('Error please Review!');

});

$scope.SubmitText = "Save";

}

}

else

$scope.meassage = "Please Insert all columns...";

}

})

.factory("Reserve", function ($http, $q) {

var fac = {};

fac.GetCountrys = function () {

return $http.get('/Home/GetCountrys')

}

fac.SaveFormData = function (data) {

var defer = $q.defer();

$http({

url: '/Home/Create',

method: "POST",

data: JSON.stringify(data),

headers: { 'content-type': 'application/json' }

});

return defer.promise;

}

return fac;

})