JSFiddle - React, Tailwind, and code Playground
HTML
<form>
<div class="answer1wrap">
<select id="mySelect">
<option value="void">Choose your answer</option>
<option value="To measure time">To measure time</option>
<option value="To measure distance">To measure distance</option>
<option value="To measure volume">To measure volume</option>
</select>
</div>
</form>
<button class="btn btn-default" id="checkbtn" onclick="answers();" type="button"><span class="glyphicon glyphicon-check"></span> Check answers</button>
JavaScript
function answers() {
var select = document.getElementById("mySelect");
var answer = select.options[select.selectedIndex].value;
if(answer == "To measure time"){
alert("Thats correct");
}
}