<!DOCTYPE html>
<html>
<head>
<title>HTML optgroup tag</title>
</head>
<body>
<select>
<optgroup label="Asia">
<option value="india">India</option>
<option value="singapore">Singapore</option>
</optgroup>
<optgroup label="Europe">
<option value="Germany">Germany</option>
<option value="France">France</option>
</optgroup>
</select>
</body>
</html>