Remove option in select

Answer 1

// As soon as all selects have one class, you'll have to distinguish them:
$(".one").each(function() { 
    // Now this corresponds to one select (in the loop over all)
    $(this).change(function() {
       // Fix what've done before
       $('option').show();
       // Find every other select, find an option in it
       // that has the same value that is selected in current select
       // (sorry for the description)
       $('.one').not(this).find('option[value=' + $(this).find('option:selected').val() +']').hide();
    });
})​;​

jsFiddle