<p>If the question had been tagged <a href="http://serverfault.com/questions/tagged/c" class="post-tag" title="show questions tagged 'c'" rel="tag">c</a>, your code block would have worked. But, it wasn't. </p>

<p>You could <em>add</em> the tag, I suppose... But that seems lame, since the question wasn't <em>about</em> C. </p>

<p>So your next best option is to simply <a href="http://meta.stackexchange.com/questions/63800/interface-options-for-specifying-language-prettify">force syntax highlighting for your code block</a>, by prefixing it with a special comment:</p>

<pre><code>&lt;!-- language: lang-c --&gt;

    ... code goes here, indented by four spaces as usual ...
</code></pre>

<p>I've done this for you. Enjoy!</p>