JSFiddle - React, Tailwind, and code Playground

HTML

<select class="mslt_Field slt_major slt_mjrpg ipt_required" id="slt_mjrpg" name="slt_mjrpg">
    <option value="">Please Select</option>
    <option value="Dip - Prof. PG Dip in Teaching ">DIP EDU</option>
    <option value="Master of Science in Finance ">MASF</option>
    <option value="MBA">MBA 2013</option>
    <option value="MHRM">MHRM</option>
    <option value="MHRM">MHRM 2005</option>
    <option value="PhD-Doctor of Business Admin">PHDBA</option>
</select>
<label>Concentration</label>
<select class="mslt_Field slt_ctr" name="slt_ctr" id="slt_ctr">
    <option value="">Please Select</option>
    <option value="MBA TESTING">TESTMBA</option>
</select>
<br/>
<label>Second row</label>
<br/>
<select class="mslt_Field slt_major slt_mjrpg1" id="slt_mjrpg1" name="slt_mjrpg">
    <option value="0">Please Select</option>
    <option value="Dip - Prof. PG Dip in Teaching ">DIP EDU</option>
    <option value="Master of Science in Finance ">MASF</option>
    <option value="MBA">MBA 2013</option>
    <option value="MHRM">MHRM</option>
    <option value="MHRM">MHRM 2005</option>
    <option value="PhD-Doctor of Business Admin">PHDBA</option>
</select>

JavaScript

$(document).ready(function () {
    $(document).on('change', 'select.slt_major', function (event) {
        var _found = false;
        var cI = $(this);
        var others = $('select.slt_major').not(cI);
        $.each(others, function () {
            if ($(cI).val() == $(this).val() && _found == false) {
                $(cI).val('');
                $('.slt_mjr1,.slt_mjrpg1,slt_mjrpg').val('0')
                $('.mjr_Desc1,.mjr_Desc,.mjr_Descpg1').val('');
                $('.pl_Stus1').val('');
                    if($('select.slt_ctr').val() != "")alert('Major already selected');
                _found = true;
            }
        });
    });
    $(".slt_ctr").children('option:gt(0)').hide();
    $("select#slt_mjrpg").on('change', function () {
        if ($(this).val() == "MBA") {
            $(".slt_ctr").children('option:gt(0)').show();
        }
    });

});