<script type="text/javascript" charset="utf-8">
	$(document).ready(function(){
 
		var dynamicOption = 'A2'; // Answer code of the dynamic dropdown option
		var toggleRadio = 'A1'; // Answer code of the "Yes" radio answer
 
		// Create a clone of the dynamic option
		var optClone = $('option[value="'+dynamicOption+'"]').clone();
 
		// Define the element directly preceding the dynamic option
		var optPre = $('option[value="'+dynamicOption+'"]').prev('option');
 
		// Initially remove the dynamic option
		$('select option[value="'+dynamicOption+'"]').remove();
 
		// Listener on the radios
		$('input.radio').click(function(){
			// If "Yes" selected, insert the dynamic option
			if($(this).attr('value') == toggleRadio) {
				if($('select option[value="'+dynamicOption+'"]').length == 0) {
					$(optPre).after(optClone);
				}
			}
			// Otherwise remove the dynamic option
			else {
				$('select option[value="'+dynamicOption+'"]').remove();
			}
		});
	});	
</script>