JSFiddle - React, Tailwind, and code Playground

HTML

<select name="product_data[29821][product_options][746]" id="option_29821_746" onchange="fn_change_options('29821', '29821', '746');" >                <option value="">Choose...</option>                                                                        <option value="3134" >Tight Buffered </option>                                                                                               <option value="3135" >Loose Tube 900um </option>       </select>

<div id="3134" class="imgDiv" style="display: none;"><img src="http://mtpassemblies.com/cs-cart/images/TB.jpg" alt="" width="500" height="290" /></div>
<div id="3135" class="imgDiv" style="display: none;"><img src="http://mtpassemblies.com/cs-cart/images/BO.jpg" alt="" width="500" height="290" /></div>

JavaScript

$(function() {
        $("select#option_29821_746").change(function() {
            $("div.imgDiv").hide();
            var targetId =  $(this).val();
            $("#" + targetId).show();
        });
    });