JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>
<ul>
<li>
  <label class="label">Age</label>
  <select id="age1">
    <option value="18">18</option><option value="19">19</option>
    <option value="20">20</option><option value="21">21</option>
    <option value="22">22</option><option value="23">23</option>
    <option value="24">24</option><option value="25">25</option>
    <option value="26">26</option><option value="27">27</option>
    <option value="28">28</option><option value="29">29</option>
    <option value="30">30</option>
  </select>
  <label class="label">To</label>
  <select id="age2">
    <option value="18">18</option><option value="19">19</option>
    <option value="20">20</option><option value="21">21</option>
    <option value="22">22</option><option value="23">23</option>
    <option value="24">24</option><option value="25">25</option>
    <option value="26">26</option><option value="27">27</option>
    <option value="28">28</option><option value="29">29</option>
    <option value="30">30</option>
  </select>
</li>
</ul>

JavaScript

$("#age1").change(function() {
	var getStartVal = $(this).val();
  $("#age2").val(getStartVal).find("option").show().each(function() {
     if($(this).attr("value")<getStartVal) {
     	$(this).hide();
     }
  });
});