如何使用viewbag对象并使用onclick进行修改？

I have a dropdown list of states with options loaded from a ViewBag. Knockout is replacing the ViewBag object with nothing. How do I A. Pass the (IEnumerable)ViewBag.States to knockout and B. Modify the drop down after an onclick event to show the modified (IEnumerable) of states. I have a dropdown list of states with options l