JQuery Remover opção de selecionar por valor
$("#FIELDID option[value='X']").remove();
Carnivorous Flamingo
$("#FIELDID option[value='X']").remove();$('.ct option').each(function() {
if ( $(this).val() == 'X' ) {
$(this).remove();
}
});
<script>
$( ".dropdown" ).change(function() {
dropdownval = $( ".dropdown" ).val();
$(".dropdown option[value='dropdownval']").remove();
});
</script>