jQuery を使用してこれを行う方法は次のとおりです。
<select id="mySelect" onchange="showhide(this)">
<option value="">Desired Home Price:</option>
<!-- the option values are suffixes for the elements to show -->
<option value="0">$200,000</option>
<option value="1">$175,000</option>
<option value="2">$150,000</option>
<option value="3">$125,000</option>
<option value="4">$100,000</option>
<option value="5">$75,000</option>
<option value="6">$50,000</option>
</select>
<div class="answer0 answers" style="width:200px;height:200px;display:none">
<div id="value1">Principal and Interest only: $898</div>
<div id="value2">Estimated total monthly payment: $1,098</div>
<div id="value3">VA loan payment:</div>
<div id="value4">Another field:</div>
</div>
<div class="answer1 answers" style="width:200px;height:200px;display:none">
<div id="value1a">Principal and Interest only: $898.00</div>
<div id="value2a">Estimated total monthly payment: $1,098.00</div>
<div id="value3a">VA loan payment:</div>
<div id="value4a">Another field:</div>
</div>
<script type="text/javascript">
function showhide(id) {
var mySel = $(id).val()
$('.answers').hide()
$('.answer'+mySel).show()
}
</script>
</p>