title: Update/Delete a sub document in mongodb using C# driver
body: <p>I have 2 classes:</p>
  
  <pre><code>public class Vote
  {
      public string VoteId { get; set; }
      public string Question { get; set; }
      public List&lt;VoteAnswer&gt; AnswerList { get; set; }
  }
  </code></pre>
  
  <p>And: </p>
  
  <pre><code>public class VoteOption
  {
      public string OptionId { get; set; }
      public string OptionName { get; set; }
      public double VoteCount { get; set; }
  }
  </code></pre>
  
  <p>How can i update/delete a <code>VoteOption</code> in a <code>Vote</code> where <code>VoteId = voteId</code> and <code>OptionId = optionId</code>? Using <code>C#</code> driver.</p>
  
  <p>First I get VoteOption by:</p>
  
  <pre><code>        var v = col.FindOneAs&lt;Vote&gt;(Query.EQ("VoteID", voteId));
          VoteOption vo = v.AnswerList.Find(x =&gt; x.OptionId == optionId);
  </code></pre>
  
  <p>End set some value to it:</p>
  
  <pre><code>vo.OptionName = "some option chose";
  vo.VoteCount = 1000;
  </code></pre>
  
  <p>But i don't know what next step to update this <code>vo</code> to <code>Vote parent</code>.</p>
  
  <p>And, if i want to delete this <code>vo</code>, show me that way!</p>
  
  <p>Data in MongoDB like that:</p>
  
  <pre><code>{
    "_id" : "460b3a7ff100",
    "Question" : "this is question?",
    "AnswerList" : [{
        "OptionId" : "1",
        "OptionName" : "Option 1",
        "VoteCount" : 0.0
      }, {
        "OptionId" : "2",
        "OptionName" : "Option 2",
        "VoteCount" : 0.0
      }, {
        "OptionId" : "3",
        "OptionName" : "Option 3",
        "VoteCount" : 0.0
      }
      }]
  }
  </code></pre>