Getting undefined in Cascading DropDownList In ASP.Core MVC

In the first DropdownList should display the Countries and in the second should display Cities based on the Country like .. USA then display just cities in USA . well i am getting undefined in dropdown city the Question is why i am getting always undefined in City dropDown list ?

here is countrol :

 public ActionResult Index()

{

Details();

return View();

}

public void Details (

{

var model = db.GetUniversities().ToList();

List li = new List();

 

li.Add(new SelectListItem { Text = "Please select Country",Value="0"});

 

foreach (var item in model)

{

li.Add(new SelectListItem { Text = item.Country, Value = item.Id.ToString()});

ViewBag.state = li;

}

[HttpPost]

public JsonResult GetCity (int id)

{

var ddlCity = db.GetUniversities().Where(x => x.Id == id).ToList();

List licities = new List();

//licities.Add(new SelectListItem { Text = "--Select City--", Value = "0" });

if (ddlCity != null)

{

 

foreach (var x in ddlCity)

{

licities.Add(new SelectListItem { Text = x.City, Value = x.Id.ToString() });

}

}

return Json(new SelectList(licities, "Text", "Value"));

}

here view