JSFiddle - React, Tailwind, and code Playground

HTML

<label class="page1">Country</label>
<div class="tooltips" title="Please select the country that the customer will primarily be served from">
    <select id="country" name="country" onchange="populate(this.id,'location')" placeholder="Phantasyland">
        <option></option>
        <option>Germany</option>
        <option>Spain</option>
        <option>Hungary</option>
        <option>USA</option>
        <option>Mexico</option>
        <option>South Africa</option>
        <option>China</option>
        <option>Russia</option>
    </select>
</div>
<br />
<br />
<label class="page1">Location</label>
<div class="tooltips" title="Please select the city that the customer is primarily to be served from.">
    <select id="location" name="location" placeholder="Anycity"></select>
</div>

JavaScript

$(document).ready(function () {
    $('#country').change(function () {
        $('#location').text() == " ";
        if ($('#country option:selected').text() == "Germany") {
            $('#location').append('<option value="Magdeburg">Magdeburg</option><option value="Duesseldorf">Duesseldorf</option><option value="Leinfelden-Echterdingen">Leinfelden-Echterdingen</option><option value="Eschborn">Eschborn</option>')
        } else if ($('#country option:selected').text == "Hungary") {
            $('#location').append('<option value="Pecs">Pecs</option><option value="Budapest">Budapest</option><option value="Debrecen">Debrecen</option>')
        } else if ($('#country option:selected').text == "Russia") {
            $('#location').append('<option value="St. Petersburg">St. Petersburg</option>')
        } else if ($('#country option:selected').text == "South Africa") {
            $('#location').append('<option value="Midrand">Midrand</option>')
        } else if ($('#country option:selected').text == "USA") {
            $('#location').append('<option value="Downers Grove">Downers Grove</option>')
        } else if ($('#country option:selected').text == "Mexico") {
            $('#location').append('<option value="Puebla">Puebla</option>')
        } else if ($('#country option:selected').text == "China") {
            $('#location').append('<option value="Beijing">Beijing</option>')
        } else if ($('#country option:selected').text == "Spain") {
            $('#location').append('<option value="Barcelona">Barcelona</option>')
        }
    });
});