JSFiddle - React, Tailwind, and code Playground

HTML

<select name = "team1">
</select>
<select name = "team2">
</select>

JavaScript

var l = [
    'Computer Science',
    'Mathematics',
    'Bioinformatic',
    'Management Sciences'
];

$('select').change(function() {
    var me = $(this);
    var other = me.siblings();
    
    var text = me.children(':selected').text();
    
    other.each(function() {
        var select = $(this);
        
        var currentText = select.children(':selected').text();
        select.empty();
        $.each(l, function(k, d) {
            if(d != text) {
                select.append($('<option></option>').html(d).attr('selected', d == currentText));
            }
        });
    });
});

$('select').change().change();