$(document).ready(function() {_x000D_
$('#YourID option[value="3"]').attr("selected", "selected");_x000D_
$('#YourID option:selected').attr("selected",null);_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.2.3/jquery.min.js"></script>_x000D_
<select id="YourID">_x000D_
<option value="1">A</option>_x000D_
<option value="2">B</option>_x000D_
<option value="3">C</option>_x000D_
<option value="4">D</option>_x000D_
</select>
_x000D_