Исправил полегче:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<script>
$('#sel option:selected').val()
$('#sel option:selected').html();
$('#sel').append( $('<option value="4">four</option>') );
$('#sel').prepend( $('<option value="-1">minus</option>') );
$('#sel option:nth-child(2)').after($('<option value="7">inserted</option>'));
$('#sel option:selected').remove();
$('#sel').empty();
$('#sel option:last').attr('selected', 'selected');
$('#sel option:nth-child(3)').attr('disabled', 'disabled');
$('#sel :not(option:selected)').css('color', 'red');
</script>
</head>
<body>
<select id="sel" name="sel">
<option value="0">zero</option>
<option value="1">one</option>
<option value="2">two</option>
<option value="3">three</option>
</select>
<div id="rates">
<input type="radio" name="rate" value="1"> 1
<input type="radio" name="rate" value="2"> 2
<input type="radio" name="rate" value="3" checked="checked"> 3
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
</body>
</html>