using ng-repeat to create dynamic rows for input fields

Very new to angularjs, so please forgive me if it is easy one.

I want to create dynamic rows for input fields, using angularjs's ng-repeat . basically i have a question object, and i want to add options to that question, by default user will have 2 rows for option, but he/she can add more options to question buy adding another row.

Jsfiddle

<div nd-repeat="option in question.options">
      <label>{{$index+1}}</label>
          <input type="text" ng-model="option.number" ng-change="change()" />
      <input type="text" ng-model="option.description" ng-change="change()" />
      <br/>
  </div>

basically i am facing 2 problems:

How should I add the new row having 2 inputs(empty) with ng-model, and read that ng-model back in controller? I do not want to new option with any empty fields, i want to have option object get added in array, and when user edits those input fields, the values should get updated in controller through ng-model

How to form the question object so i can send it to server where question object has a property as array of options (the auto-mapping should work)

here are my models at server side for question and option..

public class Option
{
    public int Number { get; set; }
    public string Description { get; set; }
}

public class Question
{
    public int Id { get; set; }
    //....opther properties
    public Option[] Options { get; set; }
}