Twitter Bootstrap 3 Checkbox Won't Align with rest of Form - html

Question

I'm having some trouble with a Twitter Bootstrap form alignment. I have a checkbox that causes the below div's to incorrectly line up with the grid because it's height is only 70px tall when the div next to it is 74px. I could add the CSS to force it to the pixel height needed (see id "test") but I don't want this stay a fixed height when content responds for smaller screens. What would be the best way to fix this?
<div class="container-fluid appointment">
<div class="container">
<div class="row">
<h2 class="text-center">Appointment Request</h2>
<form>
<div class="col-sm-4">
<div class="form-group">
<label for="">Phone Number:</label>
<input type="tel" class="form-control" id="phone">
</div>
</div>
<div class="col-sm-8">
<div class="form-group">
<label for="email">Email Address:</label>
<input type="email" class="form-control" id="email">
</div>
</div>
<div class="col-sm-7">
<div class="form-group">
<label for="petname">Pet's Name:</label>
<input type="text" class="form-control" id="petname">
</div>
</div>
<div class="col-sm-5" id="test">
<div class="form-group">
<label>Is your pet neutered or spayed?</label>
<div class="checkbox">
<label for="neutered"><input type="checkbox" id="neutspay">Neutered/Spayed</label>
</div>
</div>
</div>
<div class="col-sm-4">
<div class="form-group">
<label for="pettype">Pet Type:</label>
<select class="form-control" id="pettype">
<option>Select Pet Type...</option>
</select>
</div>
</div>
<div class="col-sm-4">
<div class="form-group">
<label for="breed">Breed Type:</label>
<select class="form-control" id="breed">
<option>Select Breed...</option>
</select>
</div>
</div>
<div class="col-sm-2">
<div class="form-group">
<label for="age">Pet Age:</label>
<select class="form-control" id="age">
<option>Select Pet Age...</option>
<option value="less than 1">Less than 1 year</option>
<option value="1">1 Year</option>
</select>
</div>
</div>
<div class="col-sm-12 text-center">
<div class="form-group">
<button type="submit" class="btn btn-lg">Send Appointment</button>
</div>
</div>
</form>
</div>
</div>
</div>

Answer 1

just add a class "clearfix" for the div containing the checkbox as
<div class="col-sm-5" id="test">
<div class="form-group clearfix">
<label>Is your pet neutered or spayed?</label>
<div class="checkbox">
<label for="neutered"><input type="checkbox" id="neutspay">Neutered/Spayed</label>
</div>
</div>
</div>