Unable to click on <label> to select a radio option in form - radio-button

Question

Working on this form - form A trying to replicate the same behaviour as you can see in this one - form B. In the form B, if you click in the <label> of each option, it just works, while in form B, you have to click each one of the <input> elements if you want to make a different choice. Why?
Both samples have not CSS included, no CSS libraries loaded, it's just HTML
Form A
<form accept-charset="UTF-8" class="edit_order" id="edit_order_260" method="post">
<div style="display:none">
<input name="utf8" type="hidden" value="✓">
<input name="_method" type="hidden" value="put">
<input name="authenticity_token" type="hidden" value="N+XdGRhPcpB+999PYEU5Bs5bvdBYkLd4Ko+cNdhoppA=">
</div>
<h3 class="panel-title">
<label for="order_Best price"><input checked="checked" id="order_delivery_option_best_price" name="order[delivery_option]" onclick="enable_submit();" type="radio" value="best_price">
Best price</label>
</h3>
<h3 class="panel-title">
<label for="order_Best delivery date"><input id="order_delivery_option_best_delivery_date" name="order[delivery_option]" onclick="enable_submit();" type="radio" value="best_delivery_date">
Best delivery date</label>
</h3>
</form>
Form B
<form role="form">
<div class="radio">
<label><input type="radio" name="optradio">Option 1</label>
</div>
<div class="radio">
<label><input type="radio" name="optradio">Option 2</label>
</div>
</form>

Answer 1

Just remove for attribute from the labels. For example:
<label><input checked="checked" id="order_delivery_option_best_price" name="order[delivery_option]" onclick="enable_submit();" type="radio" value="best_price">Best price</label>
Or make for value match the value of the id attribute of corresponding input tag. Like this:
<label for="order_delivery_option_best_price"><input checked="checked" id="order_delivery_option_best_price" name="order[delivery_option]" onclick="enable_submit();" type="radio" value="best_price">Best price</label>
In this case you don't have to nest the input inside the label and it will still work:)