Which one of the following is the correct output for the given JavaScript code?
<ol class="dp-xml" start="1">
 	<li class="alt">const <span class="attribute">obj1</span> ={ property1:'15'};</li>
 	<li class="">const <span class="attribute">obj2</span> =<span class="attribute-value">Object</span>.freeze(obj1);</li>
 	<li class="alt"><span class="attribute">obj2.property1</span>=<span class="attribute-value">'20'</span>;</li>
 	<li class="">console.log(obj2.property1);</li>
</ol>