<!DOCTYPE html>
<html>
<body>

<p>Click the button to get the text of the first child element of the select element.</p>

<select id="mySelect" size="4">
  <option>Audi</option>
  <option>BMW</option>
  <option>Saab</option>
  <option>Volvo</option>
  </select>
<br><br>

<button onclick="myFunction()">Try it</button>

<p><strong>Note:</strong> The firstElementChild property is not supported in IE8 and earlier versions.</p>

<p id="demo"></p>

<script>
function myFunction() {
    var x = document.getElementById("mySelect").firstElementChild.text;
    document.getElementById("demo").innerHTML = x;
}
</script>

</body>
</html>